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

Annotations already declare readOnlyHint and openWorldHint, and the description adds substantive behavioral context on top: fee values are in EUR, the upstream returns 50 rows per page, and its hit count is capped at 10,000. These pagination and result-cap details materially affect how an agent should page through results and are not derivable from the annotations or schema alone.

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?

It is front-loaded with purpose, then fee currency, id discovery, and pagination limits before trailing param restatements. The repeated last and likely_only sentences duplicate the schema and are the only wasted content; otherwise the structure is tight.

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 annotations covering the safety profile and an output schema handling return values, the description covers the essentials an agent needs: purpose, modes, currency, id-discovery prerequisites, and pagination limits. It is complete for a filtered list tool, with the only minor gap being the direction/filter interaction semantics.

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 every parameter including last, mode, page, fee bounds, order_by, direction, and id formats is already documented. The description merely repeats the last and likely_only definitions verbatim rather than adding new meaning (e.g., interaction between direction and filtering). This is the baseline 3 when the schema does the heavy lifting.

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 states a specific verb and resource: 'Returns confirmed transfers, rumours, or popular transfers with the public transfer-center filters,' which precisely conveys what the tool does. It also names the three feed modes. It stops short of explicitly differentiating from other providers' transfer tools (e.g., sofascore_team_transfers, flashscore_team_transfers), but no fotmob sibling duplicates this function, so ambiguity is low.

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 supplies clear routing guidance: use fotmob/leagues and fotmob/search to discover league and team ids, and use fotmob_team_news for team news. These are genuine when/prerequisite pointers. It doesn't explicitly say when to prefer confirmed vs rumours mode beyond the mode names, so it is slightly short of fully explicit exclusions.

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