Lichess MCP

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It mentions what data is returned (total games and scores) but lacks details on rate limits, authentication needs, error handling, or data freshness. For a tool with no annotation coverage, this leaves significant gaps in understanding its operational behavior.

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 front-loaded with the core purpose in the first sentence and adds clarifying detail in the second. Both sentences earn their place by providing essential information without redundancy, making it efficiently structured and easy to parse.

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 tool's low complexity (2 simple parameters) and no output schema, the description adequately covers the basic purpose and output format. However, it lacks details on behavioral aspects like rate limits or error cases, which are important for a tool with no annotations. This makes it minimally viable but with clear gaps in completeness.

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 input schema has 100% description coverage, clearly documenting both parameters as Lichess usernames. The description adds no additional parameter semantics beyond what the schema provides, such as format constraints or examples. With high schema coverage, the baseline score of 3 is appropriate as the description does not compensate but also does not detract.

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 specific action ('Get the head-to-head record') and resource ('between two Lichess players'), with explicit details on what information is returned ('Shows total games and score for each player'). It distinguishes itself from sibling tools like 'lichess_get_user' or 'lichess_get_my_games' by focusing on comparative player statistics rather than individual data or game lists.

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 implies usage when comparing two players' performance, but it does not explicitly state when to use this tool versus alternatives like 'lichess_get_user' for individual stats or 'lichess_get_my_games' for game details. No exclusions or prerequisites are mentioned, leaving the context somewhat open-ended.

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