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

With no annotations, the description carries the full behavioral burden. It usefully discloses the credit cost (1 per call) and the two output modes, but says nothing about permissions, rate limits, robots/caching behavior, JS rendering, or failure modes for an operation whose behavior an agent cannot predict.

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?

Three tight, front-loaded sentences with no filler: the action and return shape come first, the mode switch second, and the cost last. Every sentence adds information the agent can act on.

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 no output schema, the description correctly explains the return payload (title, description, clean text structure) and the cost. It omits include_links entirely and offers no guidance on pages it can or cannot scrape, but for a single-URL fetch tool it is largely sufficient.

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 description coverage is 67%: url and include_links are documented in the schema, while format is not. The description compensates for the undocumented format enum by explaining that format=html yields raw HTML, but it never mentions include_links, so it only partially fills the gap.

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/scrape) and resource (web page) plus the concrete return payload (title, description, clean readable text with headings, paragraphs, lists). This distinguishes it reasonably from single-output siblings like fetch_json or extract_tables, though it never names a sibling such as crawl_site or extract_content.

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?

The description gives no when-to-use guidance and no comparison to alternatives like crawl_site (multi-page) or extract_content. The only guidance offered, 'Use format=html for the raw HTML,' is a parameter hint rather than a selection rule, leaving the agent to infer when this tool beats its siblings.

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