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 that the article is public, that a canonical URL is required, and roughly what is returned (metadata, authors, body paragraphs), which is useful context despite overlapping with the output schema.

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 short sentences, front-loaded with the core action and followed by the routing hint. No filler; 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?

An output schema exists, so return values need no further explanation, and a single required parameter is fully documented. The description covers what the tool does, when to use it, and what it returns – nothing an agent needs to call it correctly is missing.

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% with a single url parameter already documented as 'Canonical The Motley Fool investing article URL'. The description reinforces 'by canonical URL' but adds no format or syntax guidance beyond the schema, so the baseline 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?

States a specific verb (Fetch), resource (one public Motley Fool investing article), scope (single, by canonical URL), and enumerates the returned content (metadata, authors, body paragraphs). It also names the sibling tools motleyfool_news and motleyfool_headlines as the discovery sources, so an agent can distinguish it from them without reading any 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 tells the agent when to use it ('to read a story discovered from motleyfool_news or motleyfool_headlines'), naming the alternative tools and the condition that routes to this one. No inference is required.

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