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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds genuinely non-obvious behavior: the cursor freezes a candidate window and avoids re-querying the source, and rate-limited undated searches are silently served by OpenAlex with coverage/warnings flagging the swap. That provenance disclosure is valuable context beyond 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?

Three tight sentences, front-loaded with purpose, then cursor mechanics, then the fallback caveat. Every sentence carries distinct information and none is redundant.

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, return values need not be described, and the description instead covers what matters: source, pagination model, and the rate-limit fallback. It is nearly complete, missing only explicit routing against sibling research tools.

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%, so the schema already documents all seven parameters, including the cursor's owner-bound constraint and the limit boundary. The description reinforces cursor semantics (frozen window, no new source query) but adds no syntax beyond what the schema states, so baseline 3 is correct.

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 names a specific verb and resource ("Search arXiv papers by query") and states the return shape ("normalized records and abstracts"), which clearly separates it from research_related_papers or research_read_paper. It stops short of explicitly naming a sibling the agent should prefer, so it lands at clear-but-not-differentiating.

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 gives concrete usage context for continuation ("Use an owner-bound cursor to continue the frozen candidate window without another source query") and explains the rate-limit fallback path to OpenAlex. It does not, however, state when to use this over siblings like research_related_papers or research_sources, so no explicit exclusions are present.

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