From e5fcd89942cef7006960459bbe0a8bec06dc13fb Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 23 Jul 2026 17:29:42 +0000
Subject: [PATCH 1/3] Initial plan


From 9bcd294673c875e7417e0442bb9f8a5b5331b5a6 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 23 Jul 2026 17:33:36 +0000
Subject: [PATCH 2/3] Infer defineTool handler args from schema parameters

Co-authored-by: pelikhan <4175913+pelikhan@users.noreply.github.com>
---
 README.md           | 1 +
 skills/rig/SKILL.md | 1 +
 skills/rig/rig.ts   | 5 +++++
 src/rig.test.ts     | 8 +++++---
 4 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/README.md b/README.md
index 32f7059..874a4ee 100644
--- a/README.md
+++ b/README.md
@@ -161,6 +161,7 @@ const triage = agent({
 ```
 
 Rig defaults agent tools to `skipPermission: true`, and you can also place plain tool objects in `tools`; rig will convert `s.*` parameter schemas into JSON Schema before creating the Copilot session.
+When `parameters` uses `s.*` schemas, `handler` args are inferred automatically; for plain JSON Schema, pass an explicit generic like `defineTool<{ issue: string }>(...)`.
 
 ## Evaluating agentic performance
 
diff --git a/skills/rig/SKILL.md b/skills/rig/SKILL.md
index 84b8b1c..010b41a 100644
--- a/skills/rig/SKILL.md
+++ b/skills/rig/SKILL.md
@@ -170,6 +170,7 @@ s.nonEmptyArray(s.string)  // string[] with at least one element
 ## Tools
 
 Register custom tools with `defineTool` using an SDK-neutral tool shape. Use `s.*` schemas for `parameters`. Rig defaults tools to `skipPermission: true`.
+When `parameters` uses `s.*` schemas, `handler` args are inferred automatically; for plain JSON Schema, pass an explicit generic like `defineTool<{ issue: string }>(...)`.
 
 ```ts
 import { agent, defineTool, s } from "rig";
diff --git a/skills/rig/rig.ts b/skills/rig/rig.ts
index 00746cd..d45867c 100644
--- a/skills/rig/rig.ts
+++ b/skills/rig/rig.ts
@@ -540,7 +540,12 @@ export type ToolConfig<TArgs = unknown> = {
   overridesBuiltInTool?: boolean;
   skipPermission?: boolean;
 };
+type InferToolArgs<TParameters extends ToolParameters> = TParameters extends Schema ? InferSchema<TParameters> : unknown;
 
+export function defineTool<const TParameters extends ToolParameters>(
+  name: string,
+  config: Omit<ToolConfig<InferToolArgs<TParameters>>, "parameters"> & { parameters: TParameters },
+): Tool<InferToolArgs<TParameters>>;
 export function defineTool<T = unknown>(name: string, config: ToolConfig<T>): Tool<T> {
   return {
     name,
diff --git a/src/rig.test.ts b/src/rig.test.ts
index 9a53d28..b302ad7 100644
--- a/src/rig.test.ts
+++ b/src/rig.test.ts
@@ -52,6 +52,7 @@ vi.mock("@github/copilot-sdk", () => ({
 }));
 
 import { AgentError, PromptBuilder, agent, analyzeResponse, configureAgent, copilotEngine, defineTool, p, s, toJsonSchema } from "rig";
+import type { Tool } from "rig";
 import { oncePerAgent, repair, steering, timeout } from "rig/addons";
 
 beforeEach(() => {
@@ -537,18 +538,19 @@ describe("agent invocation", () => {
   });
 
   it("defines tools with rig schemas using the Copilot SDK helper shape", () => {
-    const handler = vi.fn(async ({ issue }: { issue: string }) => `Issue ${issue}`);
     const lookupIssue = defineTool("lookup_issue", {
       description: "Look up an issue by id.",
       parameters: s.object({ issue: s.string }),
-      handler,
+      handler: vi.fn(async ({ issue }) => `Issue ${issue}`),
     });
+    const expectIssueTool = (_tool: Tool<{ issue: string }>) => true;
+    expect(expectIssueTool(lookupIssue)).toBe(true);
 
     expect(lookupIssue).toEqual({
       name: "lookup_issue",
       description: "Look up an issue by id.",
       parameters: toJsonSchema(s.object({ issue: s.string })),
-      handler,
+      handler: expect.any(Function),
       skipPermission: true,
     });
   });

From 822f67f2448689748056f7326675f4a1b6b37e95 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 23 Jul 2026 17:36:19 +0000
Subject: [PATCH 3/3] Fix defineTool overloads and infer args from schema

Co-authored-by: pelikhan <4175913+pelikhan@users.noreply.github.com>
---
 skills/rig/rig.ts | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/skills/rig/rig.ts b/skills/rig/rig.ts
index d45867c..db0c02b 100644
--- a/skills/rig/rig.ts
+++ b/skills/rig/rig.ts
@@ -546,7 +546,8 @@ export function defineTool<const TParameters extends ToolParameters>(
   name: string,
   config: Omit<ToolConfig<InferToolArgs<TParameters>>, "parameters"> & { parameters: TParameters },
 ): Tool<InferToolArgs<TParameters>>;
-export function defineTool<T = unknown>(name: string, config: ToolConfig<T>): Tool<T> {
+export function defineTool<T = unknown>(name: string, config: ToolConfig<T>): Tool<T>;
+export function defineTool(name: string, config: ToolConfig<any>): Tool<any> {
   return {
     name,
     ...normalizeToolConfig(config),