extract_emails

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

With no annotations provided, the description carries the full burden. It discloses that the tool returns JSON with results and errors, but does not explain the effect of the `js_render` parameter or any limitations such as handling of JavaScript-heavy pages or rate limits. This leaves behavioral expectations only partially specified.

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 sentences, directly stating the action and return format with no filler. Efficient.

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 description covers the basic purpose and output shape, but omits guidance on the `js_render` parameter and does not mention any edge cases or constraints. Given the availability of an output schema, the return format is documented elsewhere, but the missing parameter semantics and operational context lower the completeness.

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 coverage is 0%, so the description should explain both parameters. It clarifies that `urls` are the list of URLs to scan, but `js_render` is left undefined beyond a boolean default, leaving the agent to guess its purpose.

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 uses a specific verb ('Scan') and resource ('list of URLs for email addresses'), clearly distinguishing it from sibling extraction tools like extract_phones and extract_links.

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 states the tool's function but does not provide guidance on when to use it versus alternatives like extract_phones or crawl_site. It gives a clear task but no exclusions or alternative references.

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