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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered; the description adds useful behavior beyond that: scoring semantics ('each player receives their pair's rally points') and non-persistence ('Does not save or publish results'). It stops short of describing ranking behavior or tie handling, which would have made this a 5.

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 clarification mandate dominates the opening half, so the actual purpose arrives mid-description rather than up front, and the rules are stated at high redundancy ('ask instead of generating', 'requires clarification, not an Americano'). The guidance is valuable but could be compressed to two or three sentences without losing meaning.

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 nested-object, no-output-schema tool, the description covers the key inputs (config plus all completed previousRounds), the scoring interpretation, and the fact that nothing is persisted. What remains unexplained — the standings table shape and tie-breaking — is largely inferable from the ranking parameter documented in the schema.

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?

With 67% schema coverage, the schema does most of the work (seed, ranking modes, pointsPerMatch semantics are all documented there). The description only names the two inputs to supply ('config and all completed previousRounds') and adds one scoring rule; it contributes little parameter meaning beyond the structured fields.

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 operative sentence — 'individual PADEL Mexicano standings from completed round scores, without generating another round' — gives a specific verb, resource and scope, and implicitly separates this tool from generate_mexicano_round. However, that sentence sits after a long precondition block, so the core purpose is not front-loaded and the sibling is never named explicitly.

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?

It states explicit when-to-use ('user wants ... standings from completed round scores, without generating another round'), when-not-to-use ('ask instead of generating'), and names the alternative tool ('call get_supported_tournament_options to discover choices'). It also enumerates prohibited inferences (player/court counts, defaults, prior conversations) and hand-dates reuse of confirmed choices.

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