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

Annotations already declare readOnlyHint, idempotentHint, non-destructive, and closed-world, so the safety profile is covered. The description adds useful context about the return content and its ordering ('easiest runs first'), but says nothing about pagination, defaults, or rate limits beyond what the schema provides.

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 dense sentence that front-loads 'Use this for' and packs purpose, output shape, and sort order without filler. Slightly long but every clause carries information.

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 usefully characterizes the return (per-club fixtures, average difficulty, sorted easiest-first). Parameters are fully covered by the schema, so the definition is complete enough to call correctly, though edge behaviors (e.g., gameweek defaults) are only in the schema.

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 gw_from, gw_to, and teams are already fully documented in the schema. The description adds no parameter-level detail, so 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 resource (FPL fixture difficulty / FDR) and the concrete output ('each club's coming fixtures and their average difficulty, easiest runs first'). This clearly distinguishes it from sibling tools like get_gameweek_review or get_player, though it doesn't name an alternative explicitly.

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?

'Use this for ...' gives a clear context of when to invoke it, and the described output (easiest/hardest fixture runs) tells the agent what question it answers. It stops short of explicit when-not-to-use guidance or naming sibling alternatives, keeping it just below a 5.

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