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 the action ('send a game invite') but lacks details on permissions required, rate limits, whether the challenge is revocable, error handling, or what happens upon success/failure. For a mutation tool with zero annotation coverage, this is a significant gap in transparency.

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, well-structured sentence that efficiently conveys the tool's purpose and key parameters without redundancy. It is front-loaded with the main action and includes essential details, making it easy to understand quickly with zero wasted words.

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 complexity (a mutation with 5 parameters, no annotations, and no output schema), the description is moderately complete. It covers the core action and parameter semantics but lacks behavioral details like error handling, response format, or usage constraints. For a tool that initiates a game challenge, more context on outcomes and limitations would be beneficial.

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?

Schema description coverage is 60%, and the description adds meaningful context beyond the schema by explaining that time control includes categories like 'bullet, blitz, rapid, classical, correspondence' and specifying 'color choice' and 'rated or casual', which helps interpret parameters like 'clockLimit' and 'rated'. However, it does not fully cover all parameters (e.g., 'clockIncrement' is only briefly implied).

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 tool's purpose with a specific verb ('challenge'), resource ('a Lichess player'), and details the action ('send a game invite') with key customizable aspects (time control, color choice, rated/casual). It distinguishes itself from sibling tools like 'lichess_accept_challenge' or 'lichess_challenge_ai' by focusing on initiating a challenge to another player.

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 context by mentioning 'challenge a Lichess player' and specifying parameters like time control and rated/casual, but it does not explicitly state when to use this tool versus alternatives such as 'lichess_challenge_ai' (for AI challenges) or 'lichess_accept_challenge' (for accepting incoming challenges). No exclusions or prerequisites are provided.

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