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

Annotations only cover readOnly/openWorld, but the description adds pagination behavior (first page reports total hit count, `final` marks the last page, limit 1–100 default 20), states that zero results is a valid response, and discloses the search engine's exact-match limitation. That is substantive disclosure the annotations do not provide.

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?

Purpose, return fields, and pagination are front-loaded, and each clause carries information. It runs long as a single dense paragraph, with the matching/examples section making it heavier than strictly necessary — the two example club names could be trimmed without loss.

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?

Even though an output schema exists, the description states the returned fields (id, name, postal code, city, logo) and the total-hit-count/pagination model, and it tells the agent what to do next with a club_id. Nothing needed to call it correctly or interpret the result is missing.

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 coverage is 100%, so the baseline is 3, but the description adds real meaning the schema does not: combining text and place requires both to match (an AND-semantics rule absent from the schema), plus the offset/limit paging contract. It stops short of explaining the offset cap (0–2000) in prose.

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 opens with a specific verb and resource (search FUSSBALL.DE clubs) and names the exact query modes — club name, postcode, place, or both-must-match. It is clearly distinguishable from fussballde_club (profile lookup) and fussballde_club_matches, both of which are referenced by name.

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 explicitly says when the tool will fail (non-fuzzy matching, official names like `RasenBallsport Leipzig` vs. `RB Leipzig`) and gives concrete alternatives — search by place, one distinctive word, or use the club_id carried by team/table/match rows. The handoff to fussballde_club for the resulting club_id closes the loop.

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