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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the agent knows this is a safe, open-world read. The description adds that the feed is 'current' and 'public' and lists the returned fields, but says nothing about pagination, freshness/update cadence, or any 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?

Front-loaded with the core fetch semantics before the routing sentences, and each sentence adds distinct routing value rather than padding. Slightly verbose with four separate clauses, but no 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?

With an output schema present, the description need not explain return values, and it still names the key fields. For a zero-parameter read tool with annotations covering the safety profile, the agent has everything needed to select and call it.

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?

This tool takes no parameters, so the schema carries no semantic burden the description must compensate for. Baseline of 4 applies since there is nothing for the description to clarify or omit.

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 (The Globe and Mail's current public top-stories feed), and enumerates the returned fields (title, URL, summary, author, publication time, lead image). It distinguishes itself from globeandmail_headlines by scoping to the general top-story stream rather than section-specific lists.

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 routes the agent: use globeandmail_headlines with a supported section slug for section lists, globeandmail_sections to discover slugs, and globeandmail_article with a returned URL for full body text. Both alternatives and the conditions that select them are stated.

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