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

Annotations already declare readOnly, idempotent, openWorld, and non-destructive hints, so the bar is lower, but the description still adds meaningful behavioral detail: it will not fetch base_url, will not follow redirects, and will not retain response bodies. These are non-obvious limits that materially shape an agent's expectations and are not captured in the annotations or 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?

The description is exactly two sentences with no filler. The primary action is front-loaded in the first sentence, and the constraints are packed into one efficient clause in the second sentence. Every word 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?

The input parameters are fully documented by the schema, and the output schema covers return values, so the description only needs to carry selection-relevant behavioral context, which it does. It could define 'broken' status criteria or mention how links are extracted, but these are not required for correct invocation.

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 100%, so the baseline is 3. The description's 'up to 20 public HTTP(S) links' echoes max_links and the html source, but it does not add new parameter-level meaning beyond what the schema already provides.

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 ('check'), a resource ('up to 20 public HTTP(S) links found in supplied HTML'), and a scope ('focused'), which clearly conveys what the tool does. It hints at differentiation from broader audit/validate siblings through the word 'focused' and the explicit limitation, though it never names an alternative directly.

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 opening 'Use this for' provides an explicit scenario for when to invoke the tool, and the second sentence lists exclusions (does not fetch base_url, does not follow redirects, does not retain response bodies), which implicitly tells an agent when not to use it. It does not name specific alternative tools, but the context is strong enough for selection.

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