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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds real value beyond that: it enumerates the return contents (expected points, fixtures, best XI, captain) and states the boundary 'shows the squad and does not score it', plus the input prerequisites. It does not discuss failure modes when the team cannot be resolved.

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, each carrying distinct load: purpose and inputs first, then output contents, then the negative boundary and fallback input path. Nothing is redundant and the most decision-relevant information is front-loaded.

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 present, the description steps in by enumerating what is returned (expected points, fixtures, best XI and captain) and covers both input paths (team ID/link vs. player names). It is nearly complete for an agent to call it correctly, though it does not note behavior when neither input is supplied, even though both parameters are optional (0 required).

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 schema itself already documents the format for players ('11-15 FPL player names... e.g. Palmer CHE') and team_id ('entry ID, or any FPL link containing /entry/<id>/'). The description only restates that a team ID, link, or screenshot-derived player names are needed, so it adds little beyond the schema — the 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?

States a specific verb and resource for a specific scope: showing an FPL manager's own squad for start/bench/captain questions, with concrete output content (Copilot expected points, next-GW fixtures, best XI, captain). It also explicitly carves itself out from the scoring siblings with 'does not score it', so an agent can separate it from rate_my_team without opening either 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?

Gives clear usage context ('use this for start, bench and captain questions about an FPL manager's own squad') and an implicit exclusion via 'does not score it', which routes scoring questions elsewhere. It does not name the alternative tool (rate_my_team) directly, so the routing is inferred rather than explicit.

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