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

Annotations already declare readOnlyHint and openWorldHint, so the description adds value by disclosing sort order ('newest first'), returned fields ('start date, end date and injury type'), and result semantics ('an empty list means none recorded' and not-found for individual sports). It does not cover auth, rate limits, or pagination, keeping it from a 5.

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 compact sentences with zero waste; the core purpose is front-loaded, and the edge-case behavior follows immediately. Every clause earns its place.

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?

Given an output schema exists, the description need not explain return values in depth, but it still provides a useful summary of fields and the empty-list/not-found semantics. Together with the annotations, an agent has everything needed to call and interpret the tool.

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 id and slug parameters are fully documented in the schema. The description adds no parameter-specific syntax or format detail beyond what the schema 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?

States a specific verb and resource ('Returns a team-sport player's Flashscore injury history') and immediately distinguishes the scope by noting individual-sport players have no such page. An agent can tell this apart from general player or transfer tools 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?

Clearly identifies the applicable context (team-sport players) and gives an explicit negative case (individual-sport players return not found). It stops short of naming alternative tools for general player data or transfers, so it is not a full when-to-use/alternative mapping.

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