Add cmd/mcp-tool command for testing MCP servers
Creates sketch/cmd/mcp-tool with discover and call subcommands to manually
test MCP servers using the same mcp-go library as Sketch.
Example calls tested with Context7 MCP servers:
mcp-tool discover -mcp '{"name": "context7", "type": "http", "url": "https://mcp.context7.com/mcp"}'
mcp-tool discover -mcp '{"name": "context7-stdio", "type": "stdio", "command": "npx", "args": ["-y", "@upstash/context7-mcp"]}'
mcp-tool call -mcp '{"name": "context7-sse", "type": "sse", "url": "https://mcp.context7.com/sse"}' resolve-library-id '{"libraryName": "react"}'
mcp-tool call -mcp '{"name": "context7", "type": "http", "url": "https://mcp.context7.com/mcp"}' get-library-docs '{"context7CompatibleLibraryID": "/reactjs/react.dev", "tokens": 1000, "topic": "hooks"}'
Co-Authored-By: sketch <hello@sketch.dev>
Change-ID: s3c5c4cca2cf302d5k
diff --git a/cmd/mcp-tool/README.md b/cmd/mcp-tool/README.md
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+# mcp-tool
+
+A command-line tool for testing MCP (Model Context Protocol) servers. Uses the
+same `mcp-go` library as Sketch to provide manual testing capabilities for MCP
+server implementations.
+
+## Usage
+
+### Discover Tools
+
+List all tools available from an MCP server:
+
+```bash
+mcp-tool discover -mcp '{"name": "server-name", "type": "stdio", "command": "./server"}'
+```
+
+### Call Tools
+
+Invoke a specific tool on an MCP server:
+
+```bash
+mcp-tool call -mcp '{"name": "server-name", "type": "stdio", "command": "./server"}' tool_name '{"arg1": "value1"}'
+```
+
+## MCP Server Configuration
+
+The `-mcp` flag accepts a JSON configuration with the following fields:
+
+- `name` (required): Server name for identification
+- `type`: Transport type - "stdio" (default), "http", or "sse"
+- `command`: Command to run (for stdio transport)
+- `args`: Array of command arguments (for stdio transport)
+- `url`: Server URL (for http/sse transport)
+- `env`: Environment variables as key-value pairs (for stdio transport)
+- `headers`: HTTP headers as key-value pairs (for http/sse transport)
+
+## Examples
+
+### Stdio Transport
+
+```bash
+# Test a Python MCP server
+mcp-tool discover -mcp '{"name": "python-server", "type": "stdio", "command": "python3", "args": ["server.py"]}'
+
+# Call a tool with arguments
+mcp-tool call -mcp '{"name": "python-server", "type": "stdio", "command": "python3", "args": ["server.py"]}' list_files '{"path": "/tmp"}'
+```
+
+### HTTP Transport
+
+```bash
+# Discover tools from HTTP MCP server
+mcp-tool discover -mcp '{"name": "http-server", "type": "http", "url": "http://localhost:8080/mcp"}'
+
+# Call with custom headers
+mcp-tool call -mcp '{"name": "http-server", "type": "http", "url": "http://localhost:8080/mcp", "headers": {"Authorization": "Bearer token"}}' get_data '{}'
+```
+
+### SSE Transport
+
+```bash
+# Use Server-Sent Events transport
+mcp-tool discover -mcp '{"name": "sse-server", "type": "sse", "url": "http://localhost:8080/mcp/sse"}'
+```
+
+## Options
+
+- `-v`: Verbose output for debugging
+- `-timeout duration`: Connection timeout (default: 30s)
+
+## Testing
+
+A test MCP server (`test-mcp-server.py`) is provided in the repository root for testing purposes. It implements basic tools like `echo`, `list_files`, and `get_env`:
+
+```bash
+# Start the test server and test it
+mcp-tool discover -mcp '{"name": "test", "type": "stdio", "command": "python3", "args": ["test-mcp-server.py"]}'
+mcp-tool call -mcp '{"name": "test", "type": "stdio", "command": "python3", "args": ["test-mcp-server.py"]}' echo '{"message": "Hello MCP!"}'
+```