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

With no annotations, the description carries the disclosure burden and does it well: it reveals the paid x402 model, the $0.01 USDC-on-Base cost, and the exact retry protocol (call once without x_payment to get the challenge). It also flags that it reports risk signals and that scans are read-only in nature, though it never explicitly states the operation is non-mutating.

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 capability and its enumerated categories are front-loaded in the first sentence, followed by risk flags, use cases, batch limit, and pricing in descending order of importance. No filler sentences; every clause carries distinct information.

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?

There is no output schema, so the description must convey what comes back; it does so by listing technology categories and the specific risk flags (legacy jQuery 1.x, version-exposing generator tags, mixed content). It is slightly incomplete on the response structure — whether results are grouped per URL, include confidence, or contain version strings.

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%, and both parameters are documented in the schema, including the x_payment challenge/retry loop. The description adds only the corroborating 'up to 10 sites per call' bound and no format detail (e.g. bare domain vs. scheme handling) beyond what the schema already gives.

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 (detect) and resource (website tech stack) and enumerates exactly which technology categories are identified, so an agent knows the output scope. It is clearly distinguishable from siblings like audit_seo, audit_site_health and validate_structured_data, which target different audit concerns.

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?

It gives explicit usage contexts (sales prospecting, competitor research, security triage) and a hard operational limit of 10 sites per call, which tells the agent how to batch. It does not name a sibling alternative or state when not to use it, so it stops short of full routing guidance.

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