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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so the safety profile is covered. The description adds genuinely new behavioral context with 'Costs 1 credit', which tells the agent this call has a quota cost — information absent from every structured field. It stops short of saying whether results are cached or paginated.

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 tight sentences, front-loaded with the purpose and ending with the cost caveat. The middle field enumeration is dense and partly duplicates the output schema, but it is compactly phrased and not wasteful enough to hurt readability.

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?

With an output schema present, the definition does not need to explain return values, and the credit-cost note is a real completeness win. However, for a tool with three filter parameters and a rich sibling set, it omits any statement of what the filters do when combined (e.g. does gender narrow competitions or is it required for some leagues), leaving a real gap.

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 67% and every parameter is an enum, so the schema already carries most of the semantics. The description never mentions the format, gender or league filters as inputs — the listed attributes read as returned fields, which risks confusing a reader into thinking 'men's or women's' describes output only. Baseline 3 applies.

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 states a specific verb and resource ('see every competition we hold') and enumerates the key attributes each entry carries (format, gender, international/club, match count, dates, seasons). That is concrete enough to distinguish it from match-level siblings like get_matches or get_match, though it never names an alternative 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?

'Use to see every competition we hold' implies the discovery/overview use case, which is helpful framing. There is no when-not guidance, no mention of how it relates to get_matches or list_teams, and no statement about whether the filters narrow the returned list.

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