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

Annotations already cover read-only/idempotent/open-world, yet the description adds runtime ('up to about 45 seconds'), output volume ('counts plus up to 25 problem links'), the SSRF-style refusal of loopback/metadata targets, and the meaning of the maybe_bot_blocked flag. This is behavior beyond what the annotations declare.

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 dense sentences, front-loaded with the single-page scope, then the problem taxonomy, then the exclusion and runtime. Every clause carries an operational fact; nothing is padding.

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 shape need not be explained, and the description still covers runtime, result size, target restrictions, and flag semantics. Nothing an agent needs to decide or call 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%, so the baseline is 3; however the description grounds the `assets` parameter by naming the asset classes checked (images, scripts, stylesheets, iframes, media) and ties `max` to the 200-link cap and the 401/403/429 classification. It clarifies intent without restating schema syntax.

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 states a specific verb+resource ('Fetch ONE public web page and check ... its links and assets') and immediately bounds scope ('Not a crawler: other pages are not visited'). The uppercase ONE signals single-page semantics that could not be inferred from the name alone.

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?

It gives explicit exclusions — not a crawler, private/loopback/metadata targets refused — which tells the agent when the call will fail. There are no sibling tools to route against, and the description never states the positive use case that selects this over any other approach, so it stops short of a 5.

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