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 states the tool retrieves rating history, implying a read-only operation, but does not specify whether it requires authentication, rate limits, error conditions, or the format of the returned data. For a 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, efficient sentence: 'Get rating history of a user for all perf types'. It is front-loaded with the core purpose, contains no redundant information, and is appropriately sized for the tool's complexity. Every word earns its place, making it highly concise and well-structured.

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 lack of annotations and output schema, the description is incomplete. It does not explain what 'rating history' entails (e.g., time range, data format) or 'perf types' (e.g., specific performance categories), leaving gaps in understanding the tool's behavior and output. For a tool with no structured support, the description should provide more contextual detail to be fully helpful.

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, with one parameter 'username' clearly documented as 'Username of the player'. The description adds no additional semantic context beyond this, such as examples or constraints on the username format. Given the high schema coverage, the baseline score of 3 is appropriate, as the schema adequately handles parameter documentation.

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: 'Get rating history of a user for all perf types'. It specifies the verb ('Get'), resource ('rating history'), and scope ('for all perf types'), making the function unambiguous. However, it does not explicitly differentiate from sibling tools like 'get_user_performance' or 'get_user_profile', which might also involve user data retrieval, so it falls short of a perfect score.

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 does not mention prerequisites, such as requiring a valid username, or compare it to sibling tools like 'get_user_performance' that might offer similar or overlapping functionality. This lack of context leaves the agent to infer usage scenarios independently.

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