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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds the behavioral nuance that listed callouts are 'open' and 'could accept', which is useful context. However, it does not mention ordering, pagination, or the nature of the returned data, leaving some behavioral detail unspecified.

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 one tightly worded sentence with the core action front-loaded. It wastes no words and even embeds the optional filter logic efficiently. No redundancy or irrelevant 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?

For a simple list tool with two optional parameters and no output schema, the description conveys the essential calling context: what it lists and how to filter. The lack of return-shape information is a minor gap, but the purpose and filters are sufficient for correct invocation in most workflows.

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 0%, so the description must explain parameters. It does: 'optionally only chess' maps the game enum to the chess variant, and 'only those naming a handle' clarifies that target refers to a handle (maxLength 24). This gives enough semantic meaning for the agent to fill both parameters correctly.

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 verb (list), resource (open callouts), and adds a scope qualifier ('you could accept') that distinguishes it from pit_accept_callout. It also mentions optional filters, making the function's intent unambiguous without needing to inspect the schema.

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—listing accept-able callouts before accepting—but does not explicitly reference alternatives or when not to use it. It gives filter options but no comparison to sibling tools like pit_callout_status or pit_match_state. A more explicit routing note would improve this.

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