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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world behavior, so the safety profile needs no restating. The description adds genuine context beyond that by explaining that `url` points to a weekendgoals.com match page listing every seller and price held, which tells the agent the result is shopping-oriented. It does not describe ordering, pagination behavior, or what a fixture entry otherwise contains.

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 short sentences with no filler, and the core purpose is front-loaded. The second sentence jumps straight into a return field without transition, which is slightly abrupt but costs no clarity.

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 no output schema, the description carries more burden for explaining the return shape, yet it only documents one field (`url`). For a simple read-only list tool with fully documented parameters and complete annotations, that is adequate but leaves the agent guessing at the structure of each fixture (date, opponent, competition).

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%, and the parameter docs are rich — team-name fallback guidance, limit default of 20 with a 50 cap, and currency fallback rules. The description adds nothing about team, limit, or currency, so the baseline of 3 applies since the schema does all the work.

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-and-resource combination: a team's upcoming fixtures, explicitly scoped to home and away. An agent can tell it is team-scoped rather than venue-scoped (venue_upcoming_matches) or a general search (find_matches), but the description never names those siblings to make the distinction explicit.

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, when-not-to-use, or alternative-routing guidance at all. The scope note 'home and away' implies this covers all competitions for a team, but an agent choosing between this and find_matches must infer the boundary from the tool names alone.

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