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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds the 'App-only' hosting constraint and the UI trigger, which is modestly useful context, but says nothing about what the squad payload contains or the default/edge behavior of the gw parameter.

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 the constraint ('App-only') front-loaded and no filler. Efficient, though the second sentence is more UI-narration than agent-facing instruction.

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 read-only tool with full schema coverage, complete annotations, and no output schema, the minimum information is present. Still, the description leaves open where entry_id comes from and what the returned squad looks like, and 'App-only' is never explained.

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%: 'entry_id' is documented as the rival's FPL team id and 'gw' as a played gameweek defaulting to the last. The description adds no parameter meaning beyond the schema, so the baseline of 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?

The description states the outcome clearly — showing a rival manager's squad on a pitch — which lets an agent distinguish this from get_my_team. However, it frames the tool from a UI-trigger perspective rather than naming the verb/resource directly, and it never names a sibling to contrast against.

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 mini-league card calls this when the user taps a rival' implies the usage context (retrieving someone else's squad), and 'App-only' hints at a client restriction. But no explicit when-not to use it, no alternatives, and no prerequisites such as needing a valid entry_id from get_mini_league.

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