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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety and scope are covered. The description adds meaningful context beyond that: the content is 'public' (no auth needed) and the payload includes both metadata and body paragraphs. It does not cover failure modes (paywalls, dead URLs) or rate limits.

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 tight sentences with zero filler; the primary action is front-loaded and the routing guidance follows immediately. Every clause earns its place.

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?

Output schema exists, so return-value details are unnecessary, and annotations carry the safety profile. For a single-parameter fetch tool, the description supplies purpose, scope, and sibling routing, leaving nothing essential 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?

Schema coverage is 100%, so the url parameter is fully documented. The description's reference to the 'canonical url' essentially restates the schema's 'Canonical Breitbart article URL' description, adding no syntax or format detail. Baseline 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?

States a specific verb (Fetch) and resource (Breitbart article metadata and body paragraphs), and immediately distinguishes itself from breitbart_headlines and breitbart_news. An agent can tell exactly what this tool returns versus its siblings.

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?

Explicitly names both alternatives and the condition that selects them: breitbart_headlines for section-specific story lists and breitbart_news for the general feed, implying this tool is for a single article identified by URL. Nothing is left to inference.

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