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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds the returned field set and notes that the payload carries the article summary and source citations, which is useful behavioral 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?

Two sentences, front-loaded with the action and scope, with no filler. The second sentence restates return fields that an output schema already covers, so it is slightly redundant rather than wasted.

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 an output schema exists and annotations cover the safety profile, the description needs only to state purpose and input provenance, both of which it does. Minor gaps remain (behavior on an invalid/unknown id, any text-length or paywall limits), but nothing essential for correct invocation is missing.

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?

With a single parameter at 100% schema coverage, the schema already documents the id; the description adds provenance by specifying the id must come from the search tool, which constrains how the value is obtained. This is meaningful added meaning over the bare schema description.

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?

States a specific verb (fetches) and resource (full text of one Pollar article) and scopes it to a single item by id, which separates it from the list_*/search siblings that return collections or ids. It also anchors the resource as an 'article', distinguishing it from the get_explainer/get_film/get_event siblings that target other content types.

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 gives a clear usage context by tying the input to the search workflow ('the id returned from the search tool'), implying fetch is the follow-up step after search. It stops short of explicitly naming alternatives or stating when not to use it (e.g., for bulk retrieval), so it is clear context without exclusions.

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