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

Annotations already declare readOnlyHint, idempotentHint, and openWorldHint. The description adds return field details (citing/cited DOI pair, creation date, self-citation flag) and explains the OCI format. It does not cover error behavior, but the annotations sufficiently cover safety traits.

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, front-loaded with the action, followed by the identifier format, return values, and a usage alternative. Every sentence contributes information without redundancy.

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 only one required parameter, an output schema present, and strong annotations, the description is complete. It includes usage alternatives and return details, leaving no ambiguity for a simple single-record fetch tool.

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 has zero description coverage, but the description fully explains the `oci` parameter format: 'compound ID of the form citing-DOI__cited-DOI'. This provides essential meaning beyond the schema's type and example.

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 clearly states the tool 'Fetch one citation record by its Open Citation Identifier (OCI...)' with a specific verb and resource, and distinguishes itself from sibling tools like `citations` and `references` by noting when to use those instead.

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 provides an alternative: 'Use `citations` or `references` instead when you only have a DOI.' This gives clear when-to-use versus when-not-to-use guidance.

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