MCP Tools Reference

The KillerSkills MCP server provides four tools for searching and retrieving skills and personas. All tools use JSON-RPC 2.0 protocol over HTTP POST.

search_skills

Search the skills marketplace by query, category, runtime, or combination of filters.

Parameters

Parameter	Type	Required	Description
`query`	string	No	Search term to match against skill title, description, and tags
`category`	string	No	Filter by category (development, testing, documentation, etc.)
`runtime`	string	No	Filter by compatible runtime (claude-code, cursor, copilot, etc.)
`limit`	number	No	Maximum results to return (default: 20, max: 100)

Response

Returns an array of skills with the following fields:

slug — Unique identifier for the skill
title — Skill name
description — Brief description
category — Category classification
runtimes — Array of compatible runtimes
downloads — Total download count
ratingAvg — Average rating (1-5)

Example Request

{
  "jsonrpc": "2.0",
  "id": 3,
  "method": "tools/call",
  "params": {
    "name": "search_skills",
    "arguments": {
      "query": "typescript testing",
      "category": "testing",
      "limit": 5
    }
  }
}

Example Response

{
  "jsonrpc": "2.0",
  "id": 3,
  "result": {
    "content": [
      {
        "type": "text",
        "text": "[{\"slug\":\"jest-typescript-setup\",\"title\":\"Jest TypeScript Setup\",\"description\":\"Configure Jest for TypeScript projects with modern best practices\",\"category\":\"testing\",\"runtimes\":[\"claude-code\",\"cursor\"],\"downloads\":1247,\"ratingAvg\":4.8},{\"slug\":\"vitest-config\",\"title\":\"Vitest Configuration\",\"description\":\"Set up Vitest for blazing fast TypeScript testing\",\"category\":\"testing\",\"runtimes\":[\"claude-code\",\"cursor\",\"continue\"],\"downloads\":892,\"ratingAvg\":4.6}]"
      }
    ]
  }
}

get_skill

Retrieve the full content and metadata for a specific skill by its slug.

Parameters

Parameter	Type	Required	Description
`slug`	string	Yes	Unique skill identifier (from search results)

Response

Returns a complete skill object with:

slug — Unique identifier
title — Skill name
description — Brief description
content — Full markdown instruction body
category — Category classification
tags — Array of topic tags
runtimes — Array of compatible runtimes
author — Creator information (name, username, avatarUrl)
downloads — Total download count
ratingAvg — Average rating (1-5)
isVerified — Official verification status

Example Request

{
  "jsonrpc": "2.0",
  "id": 4,
  "method": "tools/call",
  "params": {
    "name": "get_skill",
    "arguments": {
      "slug": "jest-typescript-setup"
    }
  }
}

Example Response

{
  "jsonrpc": "2.0",
  "id": 4,
  "result": {
    "content": [
      {
        "type": "text",
        "text": "{\"slug\":\"jest-typescript-setup\",\"title\":\"Jest TypeScript Setup\",\"description\":\"Configure Jest for TypeScript projects with modern best practices\",\"content\":\"# Jest TypeScript Setup\\n\\nThis skill helps you configure Jest for TypeScript projects...\\n\\n## Installation\\n\\n```bash\\nnpm install --save-dev jest @types/jest ts-jest\\n```\\n\\n## Configuration\\n...\",\"category\":\"testing\",\"tags\":[\"jest\",\"typescript\",\"testing\",\"unit-tests\"],\"runtimes\":[\"claude-code\",\"cursor\"],\"author\":{\"name\":\"Alex Developer\",\"username\":\"alexdev\",\"avatarUrl\":\"https://avatars.killerskills.ai/avatars/user123/avatar.jpg\"},\"downloads\":1247,\"ratingAvg\":4.8,\"isVerified\":true}"
      }
    ]
  }
}

search_personas

Search the personas marketplace by query, category, runtime, or combination of filters.

Parameters

Parameter	Type	Required	Description
`query`	string	No	Search term to match against persona name, description, and tags
`category`	string	No	Filter by category (development, writing, data, etc.)
`runtime`	string	No	Filter by compatible runtime
`limit`	number	No	Maximum results to return (default: 20, max: 100)

Response

Returns an array of personas with:

slug — Unique identifier for the persona
title — Persona name
description — Brief description
category — Category classification
runtimes — Array of compatible runtimes
responseStyle — Communication style (concise, detailed, etc.)
downloads — Total download count
ratingAvg — Average rating (1-5)

Example Request

{
  "jsonrpc": "2.0",
  "id": 5,
  "method": "tools/call",
  "params": {
    "name": "search_personas",
    "arguments": {
      "query": "senior backend engineer",
      "limit": 3
    }
  }
}

Example Response

{
  "jsonrpc": "2.0",
  "id": 5,
  "result": {
    "content": [
      {
        "type": "text",
        "text": "[{\"slug\":\"senior-backend-engineer\",\"title\":\"Senior Backend Engineer\",\"description\":\"Expert in scalable backend systems, API design, and database optimization\",\"category\":\"development\",\"runtimes\":[\"claude-code\",\"cursor\",\"copilot\"],\"responseStyle\":\"technical and detailed\",\"downloads\":3421,\"ratingAvg\":4.9}]"
      }
    ]
  }
}

get_persona

Retrieve the full definition for a specific persona by its slug, including system prompt, response style, guardrails, and bundled skills.

Parameters

Parameter	Type	Required	Description
`slug`	string	Yes	Unique persona identifier (from search results)

Response

Returns a complete persona object with:

slug — Unique identifier
title — Persona name
description — Brief description
content — Full markdown content body
systemPrompt — System prompt template
responseStyle — Communication style
guardrails — Array of behavior constraints
bundledSkills — Array of included skills (each with slug, title, description, category)
author — Creator information
downloads — Total download count
ratingAvg — Average rating
isVerified — Official verification status

Example Request

{
  "jsonrpc": "2.0",
  "id": 6,
  "method": "tools/call",
  "params": {
    "name": "get_persona",
    "arguments": {
      "slug": "senior-backend-engineer"
    }
  }
}

Example Response

{
  "jsonrpc": "2.0",
  "id": 6,
  "result": {
    "content": [
      {
        "type": "text",
        "text": "{\"slug\":\"senior-backend-engineer\",\"title\":\"Senior Backend Engineer\",\"description\":\"Expert in scalable backend systems, API design, and database optimization\",\"content\":\"# Senior Backend Engineer\\n\\nA senior backend engineer persona with deep expertise...\",\"systemPrompt\":\"You are a senior backend engineer with 10+ years of experience building scalable systems. You prioritize clean architecture, performance, and reliability.\",\"responseStyle\":\"technical and detailed\",\"guardrails\":[\"Always consider scalability and performance implications\",\"Recommend established patterns over experimental approaches\",\"Include error handling and monitoring considerations\"],\"bundledSkills\":[{\"slug\":\"rest-api-design\",\"title\":\"REST API Design\",\"description\":\"Best practices for RESTful API design\",\"category\":\"development\"},{\"slug\":\"database-indexing\",\"title\":\"Database Indexing Strategy\",\"description\":\"Optimize database queries with proper indexing\",\"category\":\"development\"}],\"author\":{\"name\":\"KillerSkills Team\",\"username\":\"killerskills\",\"avatarUrl\":\"https://avatars.killerskills.ai/team/avatar.jpg\"},\"downloads\":3421,\"ratingAvg\":4.9,\"isVerified\":true}"
      }
    ]
  }
}

Error Handling

All tools return standard JSON-RPC 2.0 error responses when requests fail:

{
  "jsonrpc": "2.0",
  "id": 7,
  "error": {
    "code": -32602,
    "message": "Invalid params: slug is required"
  }
}

Common Error Codes

Code	Meaning
`-32700`	Parse error — Invalid JSON
`-32600`	Invalid request — Missing required fields
`-32601`	Method not found — Unknown tool name
`-32602`	Invalid params — Missing or invalid arguments
`-32603`	Internal error — Server-side failure

Rate Limiting

The MCP endpoint does not have strict rate limits since it only serves public data. However, excessive requests (more than 100 requests per minute) may be throttled to ensure service availability.

Next Steps

Connection Guide — Configure your AI agent to use KillerSkills
MCP Overview — Learn more about the Model Context Protocol