From c2f87853c6a8133efbcbdc48c3c2f0967f8cfb58 Mon Sep 17 00:00:00 2001
From: "opencode-agent[bot]"
 <219766164+opencode-agent[bot]@users.noreply.github.com>
Date: Tue, 6 Oct 2026 14:15:40 -0500
Subject: [PATCH] fix(core): drop tool name and namespace length caps (#53586)

Co-authored-by: rekram1-node <63023139+rekram1-node@users.noreply.github.com>
---
 packages/core/src/tool.ts                |  4 ++--
 packages/core/test/mcp.test.ts           |  7 +++----
 packages/core/test/tool-registry.test.ts | 22 ----------------------
 3 files changed, 5 insertions(+), 28 deletions(-)

diff --git a/packages/core/src/tool.ts b/packages/core/src/tool.ts
index 5e2ca8401aa..a07468a61e1 100644
--- a/packages/core/src/tool.ts
+++ b/packages/core/src/tool.ts
@@ -308,7 +308,7 @@ function registrationError(tool: Tool.Info) {
     if (error) return error
   }
   const name = normalizedName(tool)
-  if (!/^[A-Za-z0-9_-]{1,128}$/.test(name)) return new RegistrationError({ name, message: `Invalid tool name: ${name}` })
+  if (!/^[A-Za-z0-9_-]+$/.test(name)) return new RegistrationError({ name, message: `Invalid tool name: ${name}` })
   const id = effectiveName(tool)
   if (tool.options?.codemode === false && id === "execute")
     return new RegistrationError({ name: id, message: 'Tool name "execute" is reserved for CodeMode' })
@@ -321,7 +321,7 @@ function registrationError(tool: Tool.Info) {
 }
 
 function namespaceError(name: string) {
-  if (name.split(".").every((segment) => /^[A-Za-z0-9_-]{1,64}$/.test(segment))) return
+  if (name.split(".").every((segment) => /^[A-Za-z0-9_-]+$/.test(segment))) return
   return new RegistrationError({ name, message: `Invalid tool namespace: ${JSON.stringify(name)}` })
 }
 
diff --git a/packages/core/test/mcp.test.ts b/packages/core/test/mcp.test.ts
index 314b81fcb8a..5d500e5a608 100644
--- a/packages/core/test/mcp.test.ts
+++ b/packages/core/test/mcp.test.ts
@@ -2106,7 +2106,7 @@ test("serializes concurrent MCP lifecycle operations", async () => {
   )
 })
 
-testEffect(Layer.empty).live("isolates invalid MCP tools and preserves plugin transforms through catalog updates", () =>
+testEffect(Layer.empty).live("preserves plugin transforms through MCP catalog updates", () =>
   Effect.gen(function* () {
     const tool = (server: string, name: string, description = name) =>
       ({
@@ -2117,8 +2117,7 @@ testEffect(Layer.empty).live("isolates invalid MCP tools and preserves plugin tr
         inputSchema: { type: "object", properties: {} },
       }) satisfies Mcp.Tool
     const healthy = [tool("demo", "search"), tool("other", "lookup")]
-    const namespace = tool("x".repeat(65), "lookup")
-    const catalog = yield* Ref.make([tool("demo", "x".repeat(129)), ...healthy, namespace])
+    const catalog = yield* Ref.make(healthy)
 
     yield* Effect.gen(function* () {
       const registry = yield* Tool.Service
@@ -2147,7 +2146,7 @@ testEffect(Layer.empty).live("isolates invalid MCP tools and preserves plugin tr
         editor.remove("repaired_lookup")
       })
 
-      yield* Ref.set(catalog, [tool("demo", "y".repeat(129)), ...healthy, tool("demo", "added"), namespace])
+      yield* Ref.set(catalog, [...healthy, tool("demo", "added")])
       yield* bus.publish(McpEvent.ToolsChanged, { server: "demo" })
       yield* waitForTool(registry, "demo_added")
       expect((yield* toolDefinitions(registry)).map((tool) => tool.name)).toEqual([
diff --git a/packages/core/test/tool-registry.test.ts b/packages/core/test/tool-registry.test.ts
index f77e05a6630..ebda546cbc6 100644
--- a/packages/core/test/tool-registry.test.ts
+++ b/packages/core/test/tool-registry.test.ts
@@ -329,7 +329,6 @@ describe("Tool", () => {
         {
           before: make(),
           "": make(),
-          ["x".repeat(129)]: make(),
           "echo.tool": constant("first"),
           echo_tool: constant("last"),
           execute: make(),
@@ -346,27 +345,6 @@ describe("Tool", () => {
     }),
   )
 
-  it.effect("registers 128-character MCP tool names in Code Mode", () =>
-    Effect.gen(function* () {
-      const service = yield* Tool.Service
-      const name = "x".repeat(128)
-      yield* transform(service, { [name]: make(), ["x".repeat(129)]: make() }, { namespace: "cloudflare" })
-
-      const snapshot = yield* service.snapshot()
-      expect(codeModeListings(snapshot.codeModeCatalog!).map((tool) => tool.path)).toEqual([`cloudflare.${name}`])
-      const result = yield* snapshot.execute({
-        ...call("execute"),
-        call: {
-          type: "tool-call",
-          id: "call-long-mcp-name",
-          name: "execute",
-          input: { code: `return (await tools.cloudflare[${JSON.stringify(name)}]({ text: "hello" })).text` },
-        },
-      })
-      expect(result.content).toEqual([{ type: "text", text: "hello" }])
-    }),
-  )
-
   it.effect("executes native tools without requiring letter-leading names or namespace segments", () =>
     Effect.gen(function* () {
       const service = yield* Tool.Service