Skill-to-MCP

Instructions

Implementation Reference

• src/skill_to_mcp/tools/_skills.py:97-138 (handler)

  Handler function for the MCP tool 'get_skill_related_file'. Decorated with @mcp_server.tool() for automatic registration and schema inference. Delegates execution to SkillParser.get_skill_file.

  @mcp_server.tool()
  def get_skill_related_file(skill_name: str, relative_path: str, return_type: str = "both") -> "str | dict[str, str]":
      """Read the content of a specific file within a skill directory.
  
      This tool returns the requested file based on a path relative to the skill's
      SKILL.md location. Use get_skill_details() first to see the list of available files.
  
      Parameters
      ----------
      skill_name : str
          The name of the skill.
      relative_path : str
          Path to the file relative to the skill directory (e.g., "scripts/qc_core.py").
      return_type : str
          Type of data to return: "content" (default), "file_path", or "both".
          - "content": Returns only the file content as text
          - "file_path": Returns only the absolute path to the file
          - "both": Returns both content and file path in a dict
  
      Returns
      -------
      str | dict[str, str]
          If return_type is "content": The content of the requested file.
          If return_type is "file_path": The absolute path to the file.
          If return_type is "both": Dictionary with "content" and "file_path" keys.
  
      Raises
      ------
      ValueError
          If the skill or file is not found, if the path is invalid, or if return_type is invalid.
  
      Examples
      --------
      >>> content = get_skill_related_file("single-cell-rna-qc", "scripts/qc_core.py", return_type="content")
      >>> print(len(content) > 0)
      True
      """
      try:
          return skill_parser.get_skill_file(skill_name, relative_path, return_type=return_type)
      except ValueError as e:
          raise ValueError(f"Error reading skill file: {e}") from e

• src/skill_to_mcp/skill_parser.py:221-275 (helper)

  Core helper method implementing the file retrieval logic: finds skill, resolves path safely (prevents traversal), reads content or path as requested.

  def get_skill_file(
      self, skill_name: str, relative_path: str, return_type: str = "both"
  ) -> "str | dict[str, str]":
      """Get content of a specific file within a skill directory.
  
      Parameters
      ----------
      skill_name : str
          Name of the skill.
      relative_path : str
          Path relative to the skill directory.
      return_type : str
          Type of data to return: "content", "file_path", or "both" (default).
  
      Returns
      -------
      str | dict[str, str]
          If return_type is "content": Content of the requested file.
          If return_type is "file_path": Absolute path to the file.
          If return_type is "both": Dictionary with "content" and "file_path" keys.
  
      Raises
      ------
      ValueError
          If skill or file is not found, if path is invalid, or if return_type is invalid.
      """
      if return_type not in ("content", "file_path", "both"):
          raise ValueError(f"Invalid return_type: {return_type}. Must be 'content', 'file_path', or 'both'")
  
      skills = self.find_all_skills()
      for skill in skills:
          if skill.name == skill_name:
              # Validate path to prevent directory traversal
              file_path = (skill.skill_path / relative_path).resolve()
              if not file_path.is_relative_to(skill.skill_path.resolve()):
                  raise ValueError("Invalid path: attempting to access files outside skill directory")
  
              if not file_path.exists():
                  raise ValueError(f"File not found: {relative_path}")
  
              if not file_path.is_file():
                  raise ValueError(f"Path is not a file: {relative_path}")
  
              if return_type == "content":
                  return file_path.read_text(encoding="utf-8")
              elif return_type == "file_path":
                  return str(file_path)
              else:  # both
                  return {
                      "content": file_path.read_text(encoding="utf-8"),
                      "file_path": str(file_path),
                  }
  
      raise ValueError(f"Skill '{skill_name}' not found")

• src/skill_to_mcp/mcp.py:31-33 (registration)

  Invocation of register_skill_tools during MCP server initialization, which defines and registers the 'get_skill_related_file' tool among others.

  from skill_to_mcp.tools._skills import register_skill_tools
  
  register_skill_tools(mcp_server, skills_dir)