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

Beyond the readOnlyHint/openWorldHint/destructiveHint annotations, the description adds a concrete behavioral rule: for donations show donation_url or profile_url and never ask or forward a PIX key. This is useful safety context that structured 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?

Three short sentences front-load the resource and its fields, then give input-format and donation-handling guidance. No filler or repetition of schema details.

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?

The single required parameter is fully documented, an output schema exists, and the description covers input provenance plus the donation display rule. There are no material gaps for an agent to call this simple lookup tool correctly.

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%, and the schema already explains both accepted formats (short code without @ and Instagram handle without @). The description adds that the ref is returned by the NGO search, but this is a minor addition rather than a semantic clarification.

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 the resource ('Ficha de uma ONG ou protetor') and the returned content (cities served, contacts, website, donation page), making it distinct from sibling search tools like search_rescuers. It provides a clear, specific purpose for an agent.

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 explains that the accepted rescuer_ref comes from the NGO search ('devolvidos pela busca de ONGs'), which tells the agent to use search_rescuers first. It does not explicitly name the sibling or state when not to use this tool, but the context is clear enough.

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