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

Annotations already declare readOnlyHint, idempotentHint and non-destructive behavior, so the safety profile is covered. The description adds meaningful context that 'tonight' data is a prediction ('players likely to change price') rather than a fact, but it does not describe data freshness, update cadence, or result 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?

A single front-loaded sentence that leads with the trigger condition ('Use this for...') and the two view modes. No filler and nothing buried.

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, two optional parameters, full schema coverage, and safety annotations already in place, the description covers what the tool returns conceptually (rises/falls, tonight vs gameweek). It omits mention of the 'names' filtering capability, a minor gap.

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%, so the enum semantics for 'view' and the 'names' filter are fully documented in the schema. The description restates the tonight/recent split but adds no syntax or format detail beyond what the schema already provides, making the baseline 3 appropriate.

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 specific resource ('FPL price rises and falls') and the exact scope of the data, including both the predictive and retrospective modes. An agent can distinguish it from siblings like get_player or get_gameweek_review without opening the 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?

It gives clear context for when to reach for the tool ('FPL price rises and falls') and spells out the two situations it covers. It stops short of naming an alternative tool or an explicit when-not-to-use condition, so it lands at 4 rather than 5.

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