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

Annotations already provide readOnlyHint, openWorldHint, idempotentHint, and destructiveHint, indicating safe, non-destructive, idempotent behavior. The description adds that it returns observations and citation as text, providing useful behavioral context beyond 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?

Two sentences, each providing key information: what the tool does and what it returns. No extraneous words, front-loaded with the most important information.

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?

Given the existence of an output schema (not shown but indicated), the description does not need to detail return structure. It mentions observations and citation, which is sufficient for a simple fetch operation. Could add more on expected usage context but adequate.

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?

Only one parameter 'id' with 0% schema description coverage. The description compensates by specifying the expected format ('indicator/<key>/<ISO3>'), which adds essential semantic meaning beyond the bare schema.

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 it fetches full data for a result id from search, with specific format 'indicator/<key>/<ISO3>'. It distinguishes from search (which returns ids) by providing full data, and from similar tools like get_indicator by specifying return of observations and citation.

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 explicitly states this tool is for result ids returned by search, implying usage after search. It does not provide explicit when-not or alternatives, but the sibling context and timing imply appropriate usage.

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