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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety and open-world reach are covered. The description adds genuine behavioral context beyond that: the response contains story metadata and chronological post updates, telling the agent what kind of content to expect from a live blog rather than a static article.

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, both front-loaded with the action and the required input, then the return content and intended use. No filler or repetition.

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?

With an output schema present, the description needn't enumerate return fields, and it still summarizes them. Annotations cover the safety profile. The only remaining gap is guidance on obtaining the canonical URL or distinguishing it from cnn_article, which is minor.

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 with 0% schema description coverage, so the description carries the burden and mostly does: it tells the agent the URL is required and must be the 'canonical live-news URL' rather than an arbitrary CNN link. It still doesn't show a URL format or example, keeping it short of a 5.

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 and resource ('Fetch one CNN live story') and specifies the required canonical live-news URL, which separates it from the generic cnn_article sibling. It does not explicitly name a sibling, but 'live story' plus 'chronological post updates' makes the distinct resource type clear.

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?

'Use this for the latest published coverage of that story' gives implied context but never states when to choose this over cnn_article or cnn_headlines, nor any prerequisites for obtaining a canonical URL. Usage is inferrable but not spelled out.

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