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

While annotations already indicate read-only, idempotent, and non-destructive behavior, the description adds valuable behavioral context: it specifies the mechanisms (HTTP headers + HTML analysis), emphasizes passive reconnaissance, and discloses rate limits. No contradictions with annotations.

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 description is concise, front-loaded with the core purpose, and includes only high-value details: what it detects, how it detects, usage guidance, rate limits, and the return format. No redundant or filler content.

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 single-parameter tool with an output schema and strong annotations, the description is exceptionally complete. It includes the output shape, alternative tools, rate limits, and methodology, leaving no significant gaps for an agent to infer correctly.

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?

The input schema already provides a clear description for the single 'domain' parameter with examples ('example.com', 'shopify.com'). The description does not add meaningful extra parameter semantics beyond that, so the baseline score of 3 applies due to high schema coverage.

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 clearly states the tool's purpose: detecting website technology stack (CMS, frameworks, CDN, analytics, web servers, languages) via HTTP headers and HTML analysis. It explicitly lists the categories of technologies detected, distinguishing it from sibling tools like check_headers (header-only) and audit_domain (full audit).

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 description explicitly says 'Use for passive reconnaissance' and directs users to 'audit_domain' for full audits, providing a clear alternative. It also includes rate limit information (Free: 30/hr, Pro: 500/hr), which helps set expectations for usage.

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