get_prefix

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

Annotations already provide readOnlyHint and openWorldHint. The description adds one useful constraint (no list endpoint) but does not disclose other behavioral traits like the meaning of the raw parameter or the response structure. This is minimal added 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?

The description is extremely concise: two sentences with the main purpose front-loaded and a second sentence that adds a relevant limitation. No fluff or 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?

The tool is relatively simple with one required parameter and no output schema. The purpose and a key limitation are clear, but the raw parameter is undocumented and the return value is not described, leaving some ambiguity for the agent. Overall it is adequate but has clear gaps.

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 input schema has no descriptions for parameters (0% coverage). The description only gives an example for owner_prefix but leaves 'raw' entirely unexplained. This does not compensate for the lack of schema documentation, leaving the agent uncertain about the raw parameter's purpose.

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's function with a specific verb ('look up') and resource ('owner of a DOI prefix'), and provides a concrete example ('10.1038'). This distinguishes it from sibling tools like get_work or get_member, which target different entities.

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 tells users that Crossref only exposes /prefixes/{owner_prefix} and that there is no list endpoint, setting expectations that a specific prefix must be provided. However, it does not explicitly mention when not to use the tool or contrast it with alternatives.

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