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

Annotations already declare readOnly, idempotent, and non-destructive. The description adds valuable behavioral detail beyond that: long-poll semantics, early-return conditions, and the role of the since value. There is no contradiction with the annotations.

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 compact and front-loaded: a field list followed by a single sentence describing the polling behavior. Every part is informative and there is no filler or repetition of schema details.

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 there is no output schema, the description usefully enumerates the returned fields and explains the polling mode. Minor gaps remain, such as precise definitions of since and result values, but overall an agent has enough to call the tool and interpret its response.

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 only 33%, so the description must compensate. It does meaningfully: wait_seconds is explained with its polling behavior and range, and since is explained as the ply baseline for early return. Only match_id is fully covered by the schema, so the description adds real value for the other two parameters.

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 identifies the resource (match state) and enumerates the exact data returned: board, turn, legal moves, clocks, deadline_ms, result. It lacks an explicit verb, but the meaning is unambiguous and the field list differentiates it from sibling tools like pit_board_read and pit_move.

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 gives clear context for the wait_seconds parameter: it enables long-polling and explains when the call returns early (ply change, game end, or your turn). It does not name alternatives or exclusions, but the polling behavior is explicit and actionable.

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