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

The description adds real context beyond the annotations: the service calls Chess.com's Published-Data API, calls are made serially (implying rate/throughput behavior), and the data carries a non-affiliation and no-AI-training restriction. Those are useful operational and licensing caveats that the readOnlyHint and openWorldHint flags do not convey. It still says nothing about what a result set looks like in practice, how large it can get, or what happens when the club has no matches.

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?

Three sentences, front-loaded with the purpose, with no wasted filler. The second and third sentences are legal and usage caveats rather than tool mechanics, but they are short and non-redundant. Nothing important is buried.

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 and both annotations supplied, the description need not explain return values or the safety profile, and it covers the core scope adequately. However, for a list endpoint spanning three match states, it gives no sense of result size, ordering, or completeness, which leaves an agent moderately under-informed about what to expect.

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 100% and there is only one parameter, so the schema already documents the sole input. The phrase 'for one club' clarifies that the slug names a club rather than a player or tournament, which is a small increment over the schema's generic 'source slug'. Baseline 3 is appropriate given the schema does the heavy lifting.

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 opens with a specific verb and resource: 'Get registered, in-progress, and finished team matches for one club.' That enumerates the match states covered and the scoping unit (one club), which separates it from club-member or single-match tools. It loses a point only because it does not name a sibling tool or state what it is not, so an agent must infer the boundary.

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?

There is no when-to-use or when-not-to-use guidance. The description never mentions the alternatives (for example, the single-match, player-match, or club-profile siblings) or any precondition such as the club needing an active team-match program. The only usable cue is 'for one club', which an agent could infer from the required slug parameter on its own.

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