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

Annotations already cover the safety profile (readOnlyHint=true, idempotentHint=true, destructiveHint=false, openWorldHint=false), and the description adds context beyond them: this call is bound to a card-tap interaction and returns a defined content set including news and fixtures. No output schema exists, so the enumeration of returned data is genuinely useful. It omits nothing critical for a read-only lookup, though it says nothing about freshness or response shape.

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?

One sentence plus a payload enumeration, with the most important qualifier ('App-only') front-loaded. Every clause contributes — the trigger, the card purpose, and the returned data — and there is no boilerplate.

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 single-parameter read-only tool with strong annotations and no output schema, the description is nearly sufficient: it discloses the trigger and the returned content. The one meaningful gap is sibling disambiguation against `get_player` and `get_player_breakdowns`, which the agent needs in order to select correctly.

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?

There is a single required parameter and schema description coverage is 100% ('The FPL player (element) id' with min/max bounds), so the schema fully documents it. The description only says the user 'taps a player', adding no detail on id semantics, validity, or behavior for unknown ids. Baseline 3 applies when the schema carries the parameter documentation.

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 names a concrete verb-plus-resource and enumerates the payload: expected points split by gameweek and by source (minutes, goals, assists, clean sheets, bonus), fixtures, and news. That is far more specific than the title 'Player card'. It does not, however, distinguish itself from the sibling `get_player` or the similarly named `get_player_breakdowns`, so an agent must still guess which of the three to pick.

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?

'App-only. The fplcopilot card calls this when the user taps a player' hints at the trigger context, implying this is a UI-rendering path rather than a general retrieval path. But it never states when an agent should choose it over `get_player` or `get_player_breakdowns`, and 'App-only' is ambiguous — it could mean the agent should not invoke it at all. Usage is implied rather than specified.

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