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. 'Get a message thread' implies a read-only operation, but it doesn't specify permissions required, rate limits, error conditions, or what the output contains (e.g., thread metadata, messages). For a tool with no 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, clear sentence with zero wasted words. It's front-loaded and efficiently conveys the core purpose without unnecessary elaboration, making it easy for an agent to parse quickly.

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 doesn't explain what 'Get' returns (e.g., thread details, messages), error handling, or behavioral constraints. For a tool with no structured support, the description should provide more context to aid the agent in correct invocation.

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 'userId' documented as 'User ID of the other person'. The description adds no additional parameter semantics beyond this. According to the rules, with high schema coverage (>80%), the baseline score is 3, as the schema adequately handles parameter documentation without extra input from the description.

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 'Get a message thread' clearly states the verb ('Get') and resource ('message thread'), making the purpose understandable. However, it lacks specificity about what 'Get' entails (e.g., retrieve details, list messages) and doesn't distinguish this tool from potential siblings like 'send_message' or 'get_timeline', which might involve message-related operations. It's not tautological but remains vague in scope.

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 (e.g., needing an existing thread), exclusions, or how it differs from other message-related tools in the sibling list (e.g., 'send_message', 'get_timeline'). This leaves the agent without 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.