Add description and parameters to MCP server config

[viamus]

Summary

• Added description and parameters fields to McpServerConfig for documenting MCP server tools in YAML pipelines
• Created McpContextBuilder static helper that generates a ## Available MCP Tools Markdown section, automatically appended to the system prompt in StepBuilder
• These fields are YAML-only metadata — they are not sent to the Claude CLI --mcp-config JSON
• Template resolution ({{variables}}) works in description and parameter texts

YAML Example

mcp_servers:
  jira:
    command: "npx"
    args: ["-y", "@anthropic/mcp-jira"]
    description: "Search and manage Jira tickets"
    parameters:
      project_key:
        description: "The Jira project key"
        example: "PROJ-123"
    env:
      JIRA_TOKEN: "{{jira_token}}"

Generated System Prompt Section

## Available MCP Tools

### jira

Search and manage Jira tickets

**Parameters:**

- `project_key`: The Jira project key (example: `PROJ-123`)

Files Changed

File	Change
McpServerConfig.cs	Added McpParameterConfig class, Description and Parameters fields, updated ResolveTemplates
McpContextBuilder.cs	New — builds Markdown tool documentation for system prompt
StepBuilder.cs	Calls McpContextBuilder.Build() and appends to system prompt
McpServerConfigTests.cs	+5 tests for new ResolveTemplates behavior
McpContextBuilderTests.cs	New — 9 unit tests
PipelineConfigLoaderTests.cs	+1 YAML round-trip test
README.md	Added MCP Server Tools section
CLAUDE.md	New — developer context file

Test plan

• All 111 tests pass (dotnet test)
• Verify YAML with description/parameters deserializes correctly
• Verify system prompt contains MCP tool documentation when servers have metadata
• Verify --mcp-config JSON does NOT contain description/parameters

🤖 Generated with Claude Code