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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds the useful constraint that only 'public' articles are accessible, but says nothing about rate limits, paywalled content, or error behavior for invalid URLs. Adds some value beyond annotations, not a lot.

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?

A single tight sentence that front-loads the resource and enumerates the return contents. Zero wasted words.

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?

For a single-URL fetch tool with an output schema that already documents return shape, the description is nearly complete. The minor gap is what happens for a non-article or invalid URL, which is a small omission given the tool's simplicity.

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% and the single url parameter is fully documented as a 'Canonical National Post article URL'. The description adds no format or syntax detail beyond the schema, so the baseline of 3 applies.

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 names the specific resource (one National Post article) and the specific content returned (metadata and body paragraphs), which is enough to distinguish it from siblings like nationalpost_headlines or nationalpost_news that surface lists rather than a single article body. It never explicitly names those siblings, so it stops short of a 5.

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?

Usage is implied rather than stated: the URL parameter and 'one article' phrasing make clear this fetches a single article by canonical URL. There is no explicit when-to-use versus when-not, and no guidance on where a valid URL comes from (e.g. from nationalpost_news results).

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