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

Annotations only declare readOnlyHint and openWorldHint; the description contributes real behavior the annotations don't: the default season window (1 July to 30 June), that kind all is the only paged mode, and the fixed ten-match caps for next/previous/wins/draws/losses. Rate/volume limits (1-50, 0-1000) are also surfaced rather than left to the schema alone.

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?

Front-loaded with the core purpose, then the mode semantics, then the alternatives — a logical order with no filler or marketing language. The single dense sentence enumerating kind values runs long and could be bulleted, but nothing is redundant.

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?

Seven parameters, one required, with an output schema available, so return shape needn't be described. With defaults, mode semantics, pagination caps, the team_id lookup pointer, and sibling routing all covered, nothing material is missing for correct invocation.

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 100%, so the schema already explains every parameter, including kind values, defaults, and that limit/offset/date/competition_kind apply only to kind all. The description restates that relationship for emphasis but adds no syntax or format detail the schema lacks — baseline 3.

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?

Specific verb and resource: "Returns a team's matches across its competitions," followed by a precise enumeration of the five result modes. An agent can distinguish this from fussballde_club_matches and fussballde_match_plan without opening any 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?

Explicitly routes the agent away to named siblings: fussballde_team for the team profile, fussballde_match_plan for a whole competition schedule. It also states the selection condition for each kind (all = plan for a date window, next = next 10 fixtures, previous = latest 10 results, wins/draws/losses = latest 10 with that outcome).

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