Skip to content

fix: support icons in registerTool config and tools/list response #1879

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
Yanhu007 wants to merge 2 commits into
base: main
Choose a base branch
from
+14 −3
Open

fix: support icons in registerTool config and tools/list response #1879

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
4434bab
fix: support icons in registerTool config and tools/list response
Yanhu007 Apr 12, 2026
8c763a2
chore: add changeset for icons fix
Yanhu007 Apr 12, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
5 changes: 5 additions & 0 deletions .changeset/fix-register-tool-icons.md
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,5 @@
---
'@modelcontextprotocol/server': patch
---

Support `icons` in `McpServer.registerTool()` config and include it in `tools/list` responses. The MCP spec's `ToolSchema` includes `icons` via `IconsSchema`, but the high-level API did not accept or serialize it.
12 changes: 9 additions & 3 deletions packages/server/src/server/mcp.ts
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -146,6 +146,7 @@ export class McpServer {
: EMPTY_OBJECT_JSON_SCHEMA,
annotations: tool.annotations,
execution: tool.execution,
icons: tool.icons,
_meta: tool._meta
};

Expand Down Expand Up @@ -773,7 +774,8 @@ export class McpServer {
annotations: ToolAnnotations | undefined,
execution: ToolExecution | undefined,
_meta: Record<string, unknown> | undefined,
handler: AnyToolHandler<StandardSchemaWithJSON | undefined>
handler: AnyToolHandler<StandardSchemaWithJSON | undefined>,
icons?: Tool['icons'],
): RegisteredTool {
// Validate tool name according to SEP specification
validateAndWarnToolName(name);
Expand All @@ -788,6 +790,7 @@ export class McpServer {
outputSchema,
annotations,
execution,
icons,
_meta,
handler: handler,
executor: createToolExecutor(inputSchema, handler),
Expand Down Expand Up @@ -870,6 +873,7 @@ export class McpServer {
inputSchema?: InputArgs;
outputSchema?: OutputArgs;
annotations?: ToolAnnotations;
icons?: Tool['icons'];
_meta?: Record<string, unknown>;
},
cb: ToolCallback<InputArgs>
Expand All @@ -878,7 +882,7 @@ export class McpServer {
throw new Error(`Tool ${name} is already registered`);
}

const { title, description, inputSchema, outputSchema, annotations, _meta } = config;
const { title, description, inputSchema, outputSchema, annotations, icons, _meta } = config;

return this._createRegisteredTool(
name,
Expand All @@ -889,7 +893,8 @@ export class McpServer {
annotations,
{ taskSupport: 'forbidden' },
_meta,
cb as ToolCallback<StandardSchemaWithJSON | undefined>
cb as ToolCallback<StandardSchemaWithJSON | undefined>,
icons,
);
}

Expand Down Expand Up @@ -1096,6 +1101,7 @@ export type RegisteredTool = {
outputSchema?: StandardSchemaWithJSON;
annotations?: ToolAnnotations;
execution?: ToolExecution;
icons?: Tool['icons'];
_meta?: Record<string, unknown>;
handler: AnyToolHandler<StandardSchemaWithJSON | undefined>;
/** @hidden */
Expand Down
Loading