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

Annotations already cover the safety profile (readOnlyHint=true, destructiveHint=false, openWorldHint=false), so the bar is lower. The description still adds real behavioral substance: results exclude contact data, and a radius query augments results with distance_km and sorts by distance. It omits pagination/truncation behaviour and what max_results defaults to.

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 is front-loaded in the first clause, followed by tightly packed parameter rules with no filler sentences. The telegraphic style is efficient, though the compressed notation ('location = 5-stellige PLZ und radius_km') costs a little readability.

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?

For a read-only search with no output schema, the description usefully discloses what is filtered out (contact data) and what is added on radius queries. Remaining gaps are minor: no default for max_results and no hint about result volume or pagination, which an agent calling an unpaginated search would benefit from knowing.

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?

With 75% schema coverage the baseline is 3, but the description contributes beyond the schema by stating the coupling rule (radius_km only works when location is a 5-digit PLZ) and the resulting output change. It adds nothing for max_results, the one undocumented parameter.

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 gives a specific verb+resource ('Offene Gesuche suchen') and a scoping trait ('ohne Kontaktdaten') that separates it from search_providers. It never names a sibling tool explicitly, so the routing is inferred from semantics rather than stated, which keeps it below a 5.

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?

Usage context for the search itself is only implied; the only genuine guidance is parameter-level (when 'location' is a numeric prefix vs. a place name, and that radius search requires a full 5-digit PLZ). There is no statement of when to prefer this tool over search_providers or when not to use it.

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