extract_contacts

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

With no annotations, the description carries the full burden. It does disclose one meaningful trait - extraction is heuristic, implying possible false positives or partial results - which is real value. It does not say what happens when both inputs are supplied, when neither is supplied, whether pages are fetched with JS rendering, or how network failures surface.

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 definition is short, front-loaded with purpose, and the Args block is cleanly structured. The opening label "Zero-Selector Contact & Lead Intelligence" adds branding rather than information, but the rest is dense with no filler.

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-value documentation is unnecessary, and the description covers both input modes plus the extraction scope. The remaining gaps - behavior with both or neither input, and heuristic reliability expectations - are small relative to the tool's simplicity.

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 0% and the schema only carries type and default, so the description's Args block does the real work by explaining that url is a page to scrape and html_text is raw content analyzed directly, each optional if the other is given. The one unresolved point is precedence when both are provided.

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-plus-resource ("extracts") and enumerates exactly what is extracted: emails, phone numbers, WhatsApp links, social profiles, addresses, PIN/ZIP, and registration IDs. This clearly separates it from generic scraping siblings such as scrape_url or extract_structured, though it never names an alternative explicitly. The "Zero-Selector" framing is marketing-flavored rather than informative.

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?

Usage is implied by the listed extraction targets, and the parameter notes clarify that url and html_text are interchangeable inputs. However, there is no explicit statement of when to prefer this over scrape_url, extract_schema, or extract_structured, and no mention of exclusion cases.

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