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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=false, and destructiveHint=false, so the safety profile is fully covered by structured data. The description adds only the provenance note about being served by Profullstack, which is not operationally informative; it says nothing about error behavior for an unknown id. It neither contradicts nor meaningfully extends the 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?

The key information — resource plus example id — is front-loaded in the first sentence. The second sentence is boilerplate about the serving vendor and carries little selection value, though it is short enough not to be a real burden.

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 single-parameter lookup with full schema coverage and comprehensive annotations, the core needs are met. However, with no output schema, the description gives no hint of what fields a library outlet record contains, which an agent would want in order to plan around the response.

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 documents 'id' as a library outlet id, so the baseline would be 3. The description earns an extra point by supplying a concrete example id ('us.ca.lib.ca0164-002'), which conveys the expected string format that the schema does not.

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 and resource: 'One public library outlet by Datamart id,' which tells an agent exactly what entity is returned. It does not name a sibling alternative, but the resource is distinctive enough among the listed tools to be unambiguous.

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 is only implied by 'by Datamart id' — an agent can infer this is a direct lookup when an id is known rather than a search. There is no explicit when-to-use guidance, no statement of when not to use it, and no named alternative for fuzzy or list-style queries.

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