Lichess MCP

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

With no annotations provided, the description carries full burden but only states the basic action. It doesn't disclose behavioral traits like whether this requires authentication, if it's idempotent, what happens on invalid challenge IDs, or if there are rate limits—critical for a mutation tool in a gaming API context.

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 perfectly concise—two sentences with zero waste. The first sentence states the core purpose, and the second adds key optional functionality, making it front-loaded and efficient.

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?

For a mutation tool with no annotations and no output schema, the description is incomplete. It lacks critical context like authentication requirements, error handling, side effects (e.g., notifying the challenger), or what happens after declining—significant gaps given the tool's role in a real-time gaming system.

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 100%, so the schema fully documents both parameters. The description adds minimal value by mentioning the optional reason parameter but doesn't provide additional semantics beyond what's in the schema (e.g., explaining enum choices like 'tooFast' vs 'tooSlow').

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 ('Decline an incoming chess challenge') and resource ('on Lichess'), distinguishing it from sibling tools like 'lichess_accept_challenge' and 'lichess_cancel_challenge' which perform different actions on challenges.

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 ('incoming chess challenge') but doesn't explicitly state when to use this tool versus alternatives like 'lichess_accept_challenge' or 'lichess_cancel_challenge', nor does it mention prerequisites like needing an active challenge ID from 'lichess_list_challenges'.

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