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

Annotations already cover readOnly/openWorld/idempotent/non-destructive, so the safety profile is handled. The description adds genuinely useful context the annotations do not carry: 'free, no key' (auth requirement) and the shape of the return (DOIs with title, authors, publication date, container, URL). It does not mention rate limits or pagination behavior, keeping it out of the top band.

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, zero waste: capability and return shape first, routing second. No filler, no restatement of the title.

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?

With an output schema present, the description needn't detail return values, and it is complete for selecting and invoking the tool. Minor gap: no note on result limits/rate behavior beyond the schema's rows cap, but nothing essential 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% — both query and rows are documented in the schema with defaults and max. The description adds no syntax, format, or query-construction guidance beyond that, so the baseline 3 applies.

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+resource (search Crossref for scholarly works) and immediately names the sibling it competes with (openalex_works). An agent can distinguish it from the many other bibliographic tools in the sibling list without opening either schema.

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?

Explicitly routes: 'Use for DOI/citation metadata discovery; use openalex_works for citation counts and richer metadata.' Both the when and the when-not are stated with a named alternative.

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