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

Annotations already declare readOnly, idempotent, non-destructive, and openWorld, and the description is consistent with that profile (it does network fetching). It adds real value beyond annotations by disclosing that de-obfuscated emails and mailto links are resolved and naming the six platforms covered, though it says nothing about failed fetches, empty results, or rate/robots constraints.

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?

One front-loaded sentence with the action first and the extracted entity types enumerated in a compact parenthetical; no filler or redundancy.

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 usefully enumerates what comes back (emails, de-obfuscated variants, mailto links, social handles), which is the right compensation. It stops short of describing result shape (e.g., per-field lists or null handling) and edge-case behavior when nothing is found.

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% for the single 'url' parameter, so the schema carries the semantics and baseline is 3. The description only implies that the URL is a page to be fetched, adding marginal detail beyond the schema's own description.

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?

Specific verb ('Fetch a page and extract') with an enumerated resource set: emails (including de-obfuscated and mailto) and handles from six named social platforms. An agent knows exactly what this produces and can distinguish it from sibling tools like find_mentions or find_prospects.

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 'Fetch a page' framing implies usage context (you have a URL and want contact data), but there is no explicit when-to-use/when-not guidance and no routing against siblings such as find_prospects or find_mentions. Usage must be inferred.

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