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

With no annotations, the description carries the behavioral disclosure burden. It clearly states the core extractive behavior and implies a read-only operation, but it does not disclose input expectations, whether it fetches the page itself, or any limitations around link/email extraction.

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 a single compact, colon-structured sentence with no filler words. It front-loads the tool's identity and enumerates its outputs efficiently, though the brevity contributes to missing parameter guidance.

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 one-parameter tool with an output schema, the description is minimally workable: it states the core function and output categories. However, q remains semantically ambiguous and there is no mention of accepted input format or page provenance, making the description only partially complete.

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?

The schema documents only a string parameter q with a default value and 0% description coverage. The description's phrase 'on a page' hints that q is likely a page/URL, but it never explicitly names q or explains what value should be supplied, so the agent must infer the semantics.

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 identifies a concrete extraction task with a specific output resource: 'all links + external domains + emails on a page.' This is more specific than the title alone and distinguishes the tool from page-focused siblings like pageinfo and metatags, though it does not name an alternative explicitly.

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?

There is no statement about when to use this tool, what type of input it expects, or how it relates to alternatives such as email, pageinfo, or redirects. The only hint is 'on a page,' which describes the object of extraction rather than providing clear usage guidance.

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