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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false, so the safety profile is set. The description adds important behaviors beyond that: the found=true/false semantics, that found=false is a successful response, and that a malformed id triggers an INVALID_ARGUMENT error. This substantially enhances transparency beyond structured annotations.

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?

A single, information-dense sentence that front-loads the purpose and weaves in all critical details (id source, return fields, success and error cases) without any fluff. Every clause earns its place.

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 is not provided in the given definition, the description fully explains the return values (found flag, address, capacity, coordinates, page URL) and error behavior. For a simple one-parameter read-only tool, nothing an agent needs to invoke it 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 description coverage is 100%, with the parameter fully documented: 'Shelter id (UUID) from find_nearby_shelters, search_shelters or a skyddsrumskollen.nu URL.' The description mostly reiterates this source information without adding new semantic value. Baseline 3 is appropriate because the schema does the heavy lifting and the description adds minimal extra meaning.

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 ('Get details') and a precise resource ('one Swedish civil-defence shelter') identified by its SkyddsrumsKollen id. It also distinguishes itself from sibling search tools by clarifying it is a direct fetch by id, and it enumerates the returned fields. This is unambiguous and differentiates it from find_nearby_shelters and search_shelters.

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?

The description implicitly tells when to use this tool: when you already have a shelter id from a previous tool result or from a skyddsrumskollen.nu URL. It does not explicitly name sibling tools or exclude them, but the context is clear. A named alternative would push this to 5.

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