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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so safety is fully covered. The description's one addition beyond that is the result ordering ('easiest runs first'), which is genuinely useful behavioral context, but it says nothing about pagination or return shape. With annotations carrying the profile, a 3 is appropriate.

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 names the domain, the resource and the ordering with zero filler. Nothing could be trimmed without losing 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?

No output schema exists, but the description explains what is returned (coming fixtures plus average difficulty) and how it is ordered, and the fully covered schema handles the parameters. Only minor gaps remain around the return shape/format.

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 documented in the schema, including defaults and the 6-gameweek window. The description adds no syntax or format detail beyond that, 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 substance returned (each club's coming fixtures and average difficulty), with the acronym defined so an agent can map it to the domain. It does not explicitly contrast itself with any sibling such as get_gameweek_review, so it falls short of the top band.

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 Fantasy Premier League fixture difficulty' implies the retrieval context, and the ordering hint ('easiest runs first') hints at the use case. There is no statement of when NOT to use it or which sibling covers adjacent fixture questions, so the guidance is only implied.

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