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

Annotations already declare readOnly, idempotent, non-destructive and open-world behavior, so safety is covered. The description adds genuinely useful behavioral context in the form of cost ($0.003 per call) and the promise of supporting evidence per detected technology, but says nothing about latency, rate limits, or failure behavior for unreachable sites.

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?

A single dense sentence that front-loads the core action, then lists coverage breadth, then adds the cost. Every clause earns its place 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?

For a one-parameter, read-only lookup with no output schema, the description covers capability breadth, evidence returned, and price. It could be stronger by stating what the response shape looks like (e.g. per-technology evidence fields) or how unknown/unreachable sites are handled, but nothing essential to correct invocation is missing.

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?

Only one parameter, and schema description coverage is 100% with an example ('linear.app'), so the schema already does all the work. The description contributes nothing beyond what is in the schema, which is the baseline-3 case.

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+resource ('Detect what a website is built with') and enumerates the detectable categories (framework, CMS, hosting/CDN, web server, analytics, ad pixels, payments, chat, auth), making the scope concrete. It does not, however, distinguish itself from siblings like domain_report, site_metadata or security_headers, which overlap in surface area.

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 explicit when-to-use or when-not-to-use guidance and no reference to any sibling tool. An agent must infer from the category list that this is the technology-fingerprinting tool rather than one of the several adjacent domain/metadata tools.

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