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

Annotations already mark the tool as read-only and idempotent. The description goes further by disclosing that the prefix record carries only these three facts with no counts, coverage, or flags, and that the returned memberId chains into another tool. This usefully manages agent expectations about output richness.

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 sentences, each earning its place: the first defines the action and output, the second captures the user question, and the third scopes expectations and links to the sibling tool. No redundant phrases or filler.

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?

The tool has a single well-documented parameter, a clear output schema, and annotations covering safety. The description completes the picture by explaining what the result means, what it does not contain, and how to chain into crossref_get_member. Nothing essential is missing for correct invocation.

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 fully documents the `prefix` parameter, including the format and the no-suffix requirement. The tool description reinforces this with examples but adds no new semantic information beyond the schema, matching the baseline for high coverage.

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 uses a specific verb ('resolves') and resource ('DOI prefix' to 'owning Crossref member'), and names the exact output: publisher name and numeric member ID. It also differentiates itself from the sibling crossref_get_member by explaining this tool only resolves the prefix, not the full member record.

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?

The description frames the use case clearly with the question 'who publishes DOIs starting with 10.1038?' and explicitly points to crossref_get_member as the next step for a full publisher record. It does not state explicit negative conditions, but the context makes the appropriate invocation scenario obvious.

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