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

The description states that resigning a finished game is refused, which implies that a second call after a successful resignation would fail. This contradicts the annotation idempotentHint=true, which suggests the operation is idempotent and safe to retry. Thus the description conflicts with an annotation, so a score of 1 is warranted.

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 only two sentences, with no unnecessary words. It front-loads the core action and immediately provides the key behavioral constraints. Every part earns its place.

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 simple one-parameter mutation with no output schema, the description is sufficient: it states what the tool does, when it fails, and the immediate effect (game ends). No additional information is needed for an agent to call it correctly.

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 already provides full documentation for the single parameter match_id, with a description and maxLength. The tool description adds no additional meaning about the parameter, so the baseline of 3 applies since schema coverage is 100%.

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 action: 'Resign the match.' It specifies the resource (match) and the verb (resign), and adds immediate consequences ('The game ends at once') and a constraint ('resigning a finished game is refused'). This distinguishes it from sibling tools like pit_draw or pit_move, which are different actions.

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 the use case: this is the tool to give up a match. It provides a clear condition (game must not already be finished) but does not explicitly name alternatives like pit_draw or pit_move. However, the purpose is unambiguous, and the constraint is explicit.

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