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

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so the description doesn't need to re-litigate safety. It adds one genuine behavioral fact — that `url` is open access first — but says nothing about result limits, pagination, ranking, or rate limits, so it only modestly exceeds the annotation baseline.

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 short sentences, front-loaded with the action and its distinctive output. Minor ambiguity in the trailing 'Pass an `id`' clause, which reads as if `id` were an input here.

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 and rich annotations, the bar is lower and the description covers scope plus one semantic detail (open-access-first URLs). Still missing is the differentiation from the near-identical `search_papers` sibling, which is the single most decision-relevant fact an agent needs at call time.

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% for the single `query` parameter, so baseline is 3. The description adds no guidance on query syntax (boolean operators, title-only search, max 500 chars) and the second sentence about `id` refers to a parameter this tool does not have, which risks mild confusion rather than adding 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?

States a specific verb and resource ('Search scholarly papers') and even sketches the return shape ({results: [{id, title, url}]}), so the operation is unambiguous. However, the sibling list contains `search_papers`, and nothing in the description explains how this differs from it — an agent cannot tell the two apart from text alone.

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?

'Pass an `id` to fetch for the full text record' implies a follow-up path (the `fetch` sibling), which is useful workflow guidance. But there is no when-to-use/when-not guidance and no mention of when to prefer `search_papers`, `search_authors`, or `search_trials` instead.

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