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

Goes well beyond the readOnly/openWorld annotations by disclosing pagination behavior (first page reports total hit count, final marks the last page, limit 1-100 default 20, offset window) and the empty-result contract, which is exactly the kind of response-shape context an agent needs to loop over pages correctly.

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?

Front-loaded with what is searched and what is returned, then pagination, then the hard constraint, then the hand-off to the detail tool. No sentence is padding and nothing important is buried at the end.

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?

An output schema exists, so return values need no further explanation, and the description still covers the constraint, pagination, and empty-result cases. Nothing an agent needs to invoke and iterate this tool correctly 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 semantics the schema cannot express: that the first page carries the total hit count and that 'final' marks the last page, plus the cross-field rule that place cannot be used alone. That is genuine added meaning rather than restatement.

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+resource ('Searches players registered on FUSSBALL.DE') plus the filtering dimensions and the exact fields returned (id, name, birth date, team, team type). It also names the sibling it feeds into (fussballde_player), so an agent can separate search from profile retrieval without opening either 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?

Gives concrete calling conditions: at least one of first_name/last_name is required, and 'No match is a valid empty result' tells the agent an empty response is not an error. It also routes to fussballde_player for profile/season stats. It does not mention when to prefer a different discovery path (e.g. club search), so not a full 5.

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