Tech Stack

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

Annotations already declare readOnly, idempotent, non-destructive and open-world, so the safety profile is covered. The description adds real behavioral context beyond them: it fetches the homepage, follows redirects (reporting the final URL), and surfaces key response headers. Rate limits and failure behavior remain undisclosed, keeping this at a 4.

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?

Three tight sentences with the core verb+resource front-loaded, followed by detection coverage and a use case. The parenthetical examples (WordPress, Shopify, Next.js) aid agent matching, and no sentence is wasted.

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 values need not be explained, yet the description helpfully previews them anyway. For a one-parameter read-only tool with full annotation coverage, the definition is essentially complete; only edge-case/error behavior is absent.

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% for the single 'domain' parameter, including the 'Domain or full URL, e.g. shopify.com' hint, so the schema already does the work. The description adds nothing about the parameter itself; baseline 3 is appropriate.

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?

States a specific verb and resource — 'Fingerprint the technology behind a website by fetching its homepage' — and enumerates what is detected (web server, CMS/framework, CDN, analytics). An agent can immediately tell this is a tech-detection tool rather than a DNS or domain-report tool. It stops short of explicitly naming how it differs from domain_intel or dns_lookup.

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?

'Use for competitive research and lead enrichment' gives a broad context but not the conditions that select this tool over its siblings (domain_intel, dns_lookup, subdomains). No exclusions or prerequisites are stated, so the routing signal is implied rather than explicit.

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