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

No annotations are provided, so the description carries the full behavioral burden. It does disclose the meaningful behavior of the default time window (next gameweek) and the team-scope horizon (next 6 gameweeks), which an agent needs. But it says nothing about output format, ordering, or whether team is a name or ID, leaving notable gaps for a no-annotation tool.

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?

A single compact sentence, front-loaded with the primary case (fixtures for a team) and appending the alternative and default. Every clause carries information; only the slightly dense parenthetical phrasing keeps it from a 5.

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 two-param read tool with no output schema and no annotations, the description covers the core modes and default behavior adequately. It omits parameter formats and any return-shape hints, which leaves real ambiguity given the 0% schema coverage.

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 compensate, and it partially does: it explains what the team parameter scopes (next 6 gameweeks), what the gameweek parameter scopes (every fixture that round), and the default. It never specifies the expected format of 'team' (name vs ID) or the gameweek value range, so compensation is incomplete.

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?

States a specific verb+resource (get fixtures) and even delineates two scopes: a team's next 6 gameweeks vs all fixtures in a gameweek. It's clearly distinguishable from the player/team/squad siblings. It stops short of naming any sibling tool for differentiation, so it lands at a solid 4 rather than 5.

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 the two calling modes (pass a team for a rolling window, pass a gameweek for a full round) and notes the default of next gameweek. However it never states when to prefer one mode over the other or when to reach for this tool versus alternatives like team_summary. Usage is inferable but not explicit.

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