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

Annotations already declare readOnly/idempotent/non-destructive/closed-world, so the safety profile is covered. The description adds genuinely non-obvious context: the data comes from a dated export joined weekly (staleness), and 'Not listed means not in that export' clarifies negative-result semantics. It stops short of stating what the response actually contains, which matters since there is no output schema.

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 compact sentences, front-loaded with what the tool determines, followed by the usage trigger and the coverage caveat. No filler or repetition.

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 one-parameter lookup with strong annotations, the description covers purpose, trigger, data source freshness and negative-result caveats. The one remaining gap is the shape of the returned value (a status/boolean vs. a record), which the description only implies since no output schema exists.

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% and the single parameter's description already specifies accepted DOI formats (bare, doi: prefixed, doi.org URL). The description adds nothing beyond 'given DOI'. Baseline 3 is appropriate when the schema carries the full parameter burden.

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 (checks/lists) and resource (Retraction Watch database entry for a DOI), and the scope is precise: a retraction-status lookup, not a citation-graph traversal. This is clearly distinguishable from the sibling tools (what_cites, what_supports, references_of, etc.), which all deal with citation relationships rather than retraction status.

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?

Gives an explicit trigger: 'Use when a user asks whether a paper has been retracted or carries a retraction notice.' It also draws a scope boundary ('the publisher record is not checked'), which functions as a when-not. It does not name an alternative tool, but the siblings are not substitutes for this lookup, so little is left to inference.

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