lookup

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

Annotations already declare the tool read-only, idempotent, and non-destructive, so the description does not need to repeat those properties. It adds the behavioral trait of exact matching and enumerates identifier formats, but it does not disclose not-found behavior or side effects. An output schema exists, so return-value details are not required, but the behavioral disclosure is adequate rather than rich.

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?

Two sentences with no filler. The operation and accepted identifier types are front-loaded, and the routing rule is appended efficiently. Every clause adds information.

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 rich annotations and an output schema, the description covers the essential selection and invocation information. It is slightly incomplete only in not clarifying boundaries against get_report/get_fulltext and in not stating what happens when a supplied identifier is not found.

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?

The schema only defines an 'identifier' string with no description (0% coverage), so the description carries the full burden of explaining the parameter. It compensates exceptionally well by enumerating accepted forms: DOI, PMID, report number with a concrete example, transport-lit id, or landing URL. This gives an agent the concrete vocabulary needed to populate the parameter correctly.

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 opens with a concrete operation and resource: 'Exact lookup by DOI, PMID, report number (e.g. "DOT HS 813 097"), transport-lit id, or landing URL.' This clearly identifies what the tool does and the identifier forms it accepts. It also distinguishes itself from the search siblings with 'Use this instead of search when you already have an identifier,' though it does not differentiate from get_report or get_fulltext, which may also operate on identifiers.

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 explicitly states the condition to use this tool: 'Use this instead of search when you already have an identifier,' which is useful routing guidance. However, it gives no guidance on when lookup should be preferred over report- or fulltext-retrieval siblings, so the alternative-selection advice is partially incomplete.

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