Agent Skills MCP

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already indicate this is a read-only, non-destructive, idempotent, and open-world operation, covering key behavioral traits. The description adds minimal context by specifying 'key files,' but doesn't elaborate on what constitutes 'key' files, potential rate limits, or authentication needs. It doesn't contradict annotations, so a baseline score is appropriate given the annotations provide substantial information.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single, clear sentence that efficiently conveys the core action. It's front-loaded with the main purpose and avoids unnecessary details. However, it could be slightly more informative by hinting at parameters or usage context without sacrificing brevity.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the presence of annotations (which cover safety and behavior) and an output schema (which handles return values), the description doesn't need to explain those aspects. However, with 0% schema description coverage and no parameter guidance, it falls short in providing a complete understanding of how to use the tool effectively, especially for parameter semantics.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The schema description coverage is 0%, meaning parameters are undocumented in the schema. The description mentions 'specific skill directory' but doesn't explain parameters like 'skill_slug,' 'max_files,' or 'response_format.' It fails to compensate for the lack of schema documentation, leaving the agent with unclear parameter meanings beyond what's inferred from property names.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the action ('Fetch') and target ('key files for a specific skill directory from GitHub'), making the purpose understandable. However, it doesn't explicitly differentiate from sibling tools like 'github_skills_search_skills' or 'github_skills_list_repositories', which might also involve fetching skill-related data but with different scopes or methods.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides no guidance on when to use this tool versus alternatives. It doesn't mention prerequisites, such as needing a skill slug from search results, or compare it to siblings like 'github_skills_install_skill' for installation purposes or 'github_skills_search_skills' for finding skills. This leaves the agent without clear context for tool selection.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.