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

Annotations already cover read-only, idempotent, open-world, and non-destructive traits. The description adds useful behavioral context beyond that: the underlying CrossRef REST API, no-auth requirement, the registry's approximate size, and the specific returned fields (funder ID, names, location, URI).

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 compact and front-loaded, with each sentence earning its place: core purpose, returned data, and integration context (API source and auth). There is no filler or repetition that would slow an agent down.

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 simple two-parameter search tool with rich annotations, an output schema, and full schema coverage, the description is complete. It covers what the tool searches, what it returns, where the data comes from, and the fact that no authentication is required.

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 already documents both parameters fully (100% coverage), including examples and the 1-20 rows constraint. The description adds minimal new parameter meaning beyond stating that the search is 'by name,' so the baseline score of 3 is appropriate.

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 the CrossRef Funder Registry by name, returning funder IDs, names, location, and URIs. This cleanly distinguishes the tool from related CrossRef siblings like crossref.works.search and crossref.members.search by focusing on funder records.

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 gives clear usage context: use it to look up research funding organizations by name and to trace grant funding acknowledged in published papers. It does not explicitly name alternatives or provide when-not-to-use conditions, but the intended scenario is obvious.

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