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 genuinely useful context: the accepted URL shape, the rejection of wiki/video/hub pages, and what content is returned (metadata plus body paragraphs). It doesn't mention rate limits or auth, but those gaps are modest given the annotation coverage.

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, tightly front-loaded with the primary purpose, followed by the constraint and routing guidance. Every clause earns its place with no redundancy.

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 present, the description covers what the agent needs: accepted input shape, rejected page types, and sibling routing. Return-value detail is delegated to the output schema, which is appropriate.

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 baseline is 3, and with only one parameter the schema already documents it. The description goes beyond the schema's terse 'Canonical IGN article or review URL' by giving the exact URL template `https://www.ign.com/articles/<slug>`, which materially constrains valid input.

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 (IGN article or review metadata and body paragraphs), and pins the scope to a canonical article URL. It explicitly differentiates itself from ign_headlines and ign_news, so an agent can distinguish it from siblings without inspecting schemas.

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?

Gives explicit when-to-use routing ('Use ign_headlines for story lists or ign_news for the general feed') and clear when-not-to-use exclusions ('Wiki, video, and game/movie/TV hub pages are rejected'). 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.