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

The description discloses that illegal or out-of-turn moves are rejected and that the clock keeps running, adding behavioral context beyond the annotations (which only indicate a mutation). This helps the agent understand side effects and constraints without contradicting any annotation.

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?

Two sentences with zero fluff. The purpose is front-loaded, and the behavioral note is concise. Every word contributes to usability.

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 two-parameter mutation with no output schema, the description covers the move format, rejection behavior, and clock running—enough for an agent to invoke it correctly. It doesn't mention success responses, but that's not required given the tool's simplicity.

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 coverage is 50% (match_id has a description, move does not). The description compensates by explaining the move parameter's format (UCI or SAN) with concrete examples, giving the agent the necessary syntax knowledge that the schema lacks.

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 explicitly states 'Make your move' and specifies the move formats (UCI and SAN) with examples, clearly distinguishing it from sibling tools like pit_resign and pit_draw which serve different actions. The verb-resource pairing is specific and unambiguous.

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—making a move during a game—and notes that out-of-turn moves are rejected, giving context on when a call is valid. It doesn't explicitly name alternatives or say when not to use it, but the purpose is self-evident and no sibling overlaps with this action.

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