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 behavior are covered. The description usefully adds that the data is public and comes from an RSS feed (implying freshness, no auth), but says nothing about result volume, pagination, or recency window.

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, zero filler, with the core behavior front-loaded and the sibling routing placed second. 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?

With an output schema present, the description needn't explain return shape, and annotations cover the safety profile. The description supplies source, freshness, and sibling routing, which is enough for a no-param feed tool; only recency/pagination expectations are left implicit.

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 tool takes zero parameters, so there is nothing for the description to disambiguate; a baseline of 4 applies. The schema's additionalProperties=false correctly confirms a no-arg call.

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 (Returns) and resource (fresh National Post stories) and pins the source (the public site-wide RSS feed). It also names the sibling nationalpost_headlines and the distinction (site-wide feed vs section headlines), so an agent can route without opening a schema.

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 directs the agent to nationalpost_headlines when section headlines are wanted, which implies this tool is for the broader site-wide feed. It gives a clear routing rule but stops short of stating exclusions or other alternatives (e.g. nationalpost_article, nationalpost_sections).

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