diff --git a/packages/codemode/src/tool-runtime.ts b/packages/codemode/src/tool-runtime.ts
index e30cb1108e7..e05e2090028 100644
--- a/packages/codemode/src/tool-runtime.ts
+++ b/packages/codemode/src/tool-runtime.ts
@@ -176,7 +176,7 @@ const describeTool = <R>(visible: VisibleTool<R>): ToolDescription => {
       // Joining the final fragments avoids retaining the rendering's intermediate string ropes in JSC.
       return (signature ??= [
         toolExpression(visible.path),
-        isEmptyInput(visible.tool) ? "()" : `(input: ${inputTypeScript(visible.tool, true)})`,
+        isEmptyInput(visible.tool) ? "()" : `(${inputTypeScript(visible.tool, true)})`,
         `: Promise<${outputTypeScript(visible.tool, true)}>`,
       ].join(""))
     },
@@ -279,7 +279,7 @@ const makeSearchTool = (searchIndex: ReadonlyArray<SearchEntry>): Tool => ({
 /** Exact callable signature of the built-in `search` function, for host-owned instructions. */
 export const searchSignature = (() => {
   const tool = makeSearchTool([])
-  return `search(input: ${inputTypeScript(tool, true)}): ${outputTypeScript(tool, true)}`
+  return `search(${inputTypeScript(tool, true)}): ${outputTypeScript(tool, true)}`
 })()
 
 const toSearchEntry = <R>(visible: VisibleTool<R>): SearchEntry => ({
diff --git a/packages/codemode/test/codemode.test.ts b/packages/codemode/test/codemode.test.ts
index 1336a775bd3..24d7da80f21 100644
--- a/packages/codemode/test/codemode.test.ts
+++ b/packages/codemode/test/codemode.test.ts
@@ -581,7 +581,7 @@ describe("CodeMode schema flexibility", () => {
       {
         path: "adapter.call",
         description: "Call an adapter-described tool",
-        signature: "tools.adapter.call(input: {\n  id: string,\n  count?: number,\n}): Promise<void>",
+        signature: "tools.adapter.call({\n  id: string,\n  count?: number,\n}): Promise<void>",
       },
     ])
 
@@ -664,7 +664,7 @@ describe("CodeMode schema flexibility", () => {
       {
         path: "users.lookup",
         description: "Look up a user",
-        signature: "tools.users.lookup(input: {\n  login: string,\n}): Promise<{\n  login: string,\n  id: number,\n}>",
+        signature: "tools.users.lookup({\n  login: string,\n}): Promise<{\n  login: string,\n  id: number,\n}>",
       },
     ])
 
@@ -680,7 +680,7 @@ describe("CodeMode schema flexibility", () => {
       execute: () => Effect.succeed("pong"),
     })
     const runtime = CodeMode.make({ tools: { net: { ping } } })
-    expect(runtime.catalog[0]?.signature).toBe("tools.net.ping(input: {\n  host: string,\n}): Promise<void>")
+    expect(runtime.catalog[0]?.signature).toBe("tools.net.ping({\n  host: string,\n}): Promise<void>")
 
     const result = await Effect.runPromise(runtime.execute(`return await tools.net.ping({ host: "example.test" })`))
     expect(result.ok).toBe(true)
@@ -737,7 +737,7 @@ describe("CodeMode public contract", () => {
       {
         path: "orders.lookup",
         description: "Look up an order by ID",
-        signature: "tools.orders.lookup(input: {\n  id: string,\n}): Promise<{\n  id: string,\n  status: string,\n}>",
+        signature: "tools.orders.lookup({\n  id: string,\n}): Promise<{\n  id: string,\n  status: string,\n}>",
       },
     ])
 
@@ -749,8 +749,7 @@ describe("CodeMode public contract", () => {
           {
             path: "tools.orders.lookup",
             description: "Look up an order by ID",
-            signature:
-              "tools.orders.lookup(input: {\n  id: string,\n}): Promise<{\n  id: string,\n  status: string,\n}>",
+            signature: "tools.orders.lookup({\n  id: string,\n}): Promise<{\n  id: string,\n  status: string,\n}>",
           },
         ],
         remaining: 0,
@@ -792,7 +791,7 @@ describe("CodeMode public contract", () => {
       {
         path: "context7.resolve-library-id",
         description: "Resolve a library ID",
-        signature: 'tools.context7["resolve-library-id"](input: {\n  libraryName: string,\n}): Promise<string>',
+        signature: 'tools.context7["resolve-library-id"]({\n  libraryName: string,\n}): Promise<string>',
       },
     ])
 
@@ -804,7 +803,7 @@ describe("CodeMode public contract", () => {
           {
             path: 'tools.context7["resolve-library-id"]',
             description: "Resolve a library ID",
-            signature: 'tools.context7["resolve-library-id"](input: {\n  libraryName: string,\n}): Promise<string>',
+            signature: 'tools.context7["resolve-library-id"]({\n  libraryName: string,\n}): Promise<string>',
           },
         ],
         remaining: 0,
@@ -857,12 +856,12 @@ describe("CodeMode public contract", () => {
         {
           path: "tools.thread.uploadFile",
           description: "Upload one readable local file to the current Discord thread",
-          signature: "tools.thread.uploadFile(input: {\n  path: string,\n}): Promise<{\n  sent: boolean,\n}>",
+          signature: "tools.thread.uploadFile({\n  path: string,\n}): Promise<{\n  sent: boolean,\n}>",
         },
         {
           path: "tools.thread.generateImage",
           description: "Generate an image and upload it to the current Discord thread",
-          signature: "tools.thread.generateImage(input: {\n  prompt: string,\n}): Promise<{\n  sent: boolean,\n}>",
+          signature: "tools.thread.generateImage({\n  prompt: string,\n}): Promise<{\n  sent: boolean,\n}>",
         },
       ],
       remaining: 0,
@@ -950,7 +949,7 @@ describe("CodeMode public contract", () => {
             {
               path: "tools.many.tool13",
               description: "Numbered tool 13",
-              signature: "tools.many.tool13(input: {\n  id: string,\n}): Promise<string>",
+              signature: "tools.many.tool13({\n  id: string,\n}): Promise<string>",
             },
           ],
           remaining: 0,
diff --git a/packages/codemode/test/signature.test.ts b/packages/codemode/test/signature.test.ts
index 96d3122a3bf..5b9c98d1a6d 100644
--- a/packages/codemode/test/signature.test.ts
+++ b/packages/codemode/test/signature.test.ts
@@ -739,7 +739,7 @@ describe("JSDoc signatures in catalogs and search results", () => {
       "  },",
       "}",
     ].join("\n")
-    const signature = `tools.constrained(input: ${type}): Promise<${type}>`
+    const signature = `tools.constrained(${type}): Promise<${type}>`
     expect(runtime.catalog[0]?.signature).toBe(signature)
     const result = await Effect.runPromise(runtime.execute('return search({ query: "tools.constrained" })'))
     expect(result.ok).toBe(true)
@@ -761,7 +761,7 @@ describe("JSDoc signatures in catalogs and search results", () => {
     const item = items.find(({ path }) => path === "tools.github.list_issues")!
     expect(item.signature).toBe(
       [
-        "tools.github.list_issues(input: {",
+        "tools.github.list_issues({",
         "  /** Repository owner */",
         "  owner: string,",
         "  /** Cursor from the previous response's pageInfo */",
@@ -782,7 +782,7 @@ describe("JSDoc signatures in catalogs and search results", () => {
       const item = items.find(({ path }) => path === "tools.orders.lookup")!
       expect(item.signature).toBe(
         [
-          "tools.orders.lookup(input: {",
+          "tools.orders.lookup({",
           "  /** Order identifier */",
           "  id: string,",
           "  verbose?: boolean,",
@@ -825,7 +825,7 @@ describe("non-identifier tool paths", () => {
 
   test("catalog signatures use bracket notation for dashed tool names", () => {
     expect(runtime.catalog[0]?.signature).toBe(
-      'tools.context7["resolve-library-id"](input: {\n  query: string,\n  libraryName: string,\n}): Promise<unknown>',
+      'tools.context7["resolve-library-id"]({\n  query: string,\n  libraryName: string,\n}): Promise<unknown>',
     )
   })
 
@@ -836,6 +836,6 @@ describe("non-identifier tool paths", () => {
 
     const value = result.value as { items: Array<{ path: string; signature: string }> }
     expect(value.items[0]?.path).toBe('tools.context7["resolve-library-id"]')
-    expect(value.items[0]?.signature).toContain('tools.context7["resolve-library-id"](input: {')
+    expect(value.items[0]?.signature).toContain('tools.context7["resolve-library-id"]({')
   })
 })
diff --git a/packages/core/test/codemode.test.ts b/packages/core/test/codemode.test.ts
index 8f94541bdca..59a26dbb08a 100644
--- a/packages/core/test/codemode.test.ts
+++ b/packages/core/test/codemode.test.ts
@@ -30,7 +30,7 @@ describe("CodeMode", () => {
             type: "tool",
             name: "echo",
             description: "Echo text",
-            signature: "tools.echo(input: {\n  text: string,\n}): Promise<string>",
+            signature: "tools.echo({\n  text: string,\n}): Promise<string>",
             pinned: true,
           },
           {
diff --git a/packages/core/test/codemode/catalog.test.ts b/packages/core/test/codemode/catalog.test.ts
index c15fee05e12..520ae8e8960 100644
--- a/packages/core/test/codemode/catalog.test.ts
+++ b/packages/core/test/codemode/catalog.test.ts
@@ -6,14 +6,14 @@ const entry = (path: string, description: string, signature?: string, pinned = f
   type: "tool",
   name: path,
   description,
-  signature: signature ?? `tools.${path}(input: {\n  q: string,\n}): Promise<string>`,
+  signature: signature ?? `tools.${path}({\n  q: string,\n}): Promise<string>`,
   pinned,
 })
 
 const lookup = entry(
   "orders.lookup",
   "Look up an order by ID",
-  "tools.orders.lookup(input: {\n  id: string,\n}): Promise<{\n  id: string,\n  status: string,\n}>",
+  "tools.orders.lookup({\n  id: string,\n}): Promise<{\n  id: string,\n  status: string,\n}>",
 )
 
 const render = (tools: CodeModeCatalog.Inventory["tools"], budget?: number) =>
@@ -133,7 +133,7 @@ describe("CodeModeInstructions.render", () => {
     expect(partial).toContain(
       "The catalog is partial. Inside `execute`, use `search(...)` to find a tool, then call it by the `path` in the result. `search` is synchronous. Call it without `await`; it does not return a Promise.",
     )
-    expect(partial).toContain("- search(input: {")
+    expect(partial).toContain("- search({")
     expect(partial).toContain("  /** @integer @exclusiveMinimum 0 */\n  limit?: number,")
     expect(partial).toContain("  /** @integer @minimum 0 */\n  offset?: number,")
     expect(partial).not.toContain("tools.orders.lookup(input:")
@@ -145,7 +145,7 @@ describe("CodeModeInstructions.render", () => {
     const expensive = entry(
       "alpha.expensive",
       "Expensive",
-      `tools.alpha.expensive(input: {\n  aVeryLongParameterName: string,\n  anotherEvenLongerParameterName: number,\n  yetAnotherExtremelyVerboseParameterName: string,\n}): Promise<string>`,
+      `tools.alpha.expensive({\n  aVeryLongParameterName: string,\n  anotherEvenLongerParameterName: number,\n  yetAnotherExtremelyVerboseParameterName: string,\n}): Promise<string>`,
     )
     // Round 1 places alpha.cheap and beta.cheap; in round 2 alpha.expensive does not fit,
     // which marks only alpha done - it must NOT prevent other namespaces from inlining.
@@ -166,7 +166,7 @@ describe("CodeModeInstructions.render", () => {
     const documented = entry(
       "records.lookup",
       "Look up a record",
-      `tools.records.lookup(input: {\n  /** ${"A detailed identifier description. ".repeat(20).trim()} */\n  id: string,\n}): Promise<string>`,
+      `tools.records.lookup({\n  /** ${"A detailed identifier description. ".repeat(20).trim()} */\n  id: string,\n}): Promise<string>`,
     )
     const instructions = render([documented], 40)
     expect(instructions).toContain("- records (1 tool, none shown)")
@@ -184,7 +184,7 @@ describe("CodeModeInstructions.update", () => {
   const echo = entry("notes.echo", "Echo text")
 
   test("renders additions, changes, and removals as a compact semantic delta", () => {
-    const changed = { ...echo, signature: "tools.notes.echo(input: {\n  text: string,\n}): Promise<string>" }
+    const changed = { ...echo, signature: "tools.notes.echo({\n  text: string,\n}): Promise<string>" }
     const added = entry("notes.list", "List notes")
     const unchanged = Array.from({ length: 5 }, (_, index) => entry(`stable.tool${index}`, `Stable ${index}`))
     const text = update([echo, lookup, ...unchanged], [changed, added, ...unchanged])
diff --git a/packages/core/test/codemode/instructions.test.ts b/packages/core/test/codemode/instructions.test.ts
index 89270749316..5c6f760f403 100644
--- a/packages/core/test/codemode/instructions.test.ts
+++ b/packages/core/test/codemode/instructions.test.ts
@@ -13,14 +13,14 @@ const echo: CodeModeCatalog.Tool = {
   type: "tool",
   name: "notes.echo",
   description: "Echo text",
-  signature: "tools.notes.echo(input: {\n  text: string,\n}): Promise<string>",
+  signature: "tools.notes.echo({\n  text: string,\n}): Promise<string>",
 }
 
 const lookup: CodeModeCatalog.Tool = {
   type: "tool",
   name: "orders.lookup",
   description: "Look up an order",
-  signature: "tools.orders.lookup(input: {\n  id: string,\n}): Promise<unknown>",
+  signature: "tools.orders.lookup({\n  id: string,\n}): Promise<unknown>",
 }
 
 describe("CodeModeInstructions", () => {