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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint false, covering the safety profile. The description adds valuable behavioral context by stating that each technology returns evidence (response header, cookie name, script) for checkability. This goes beyond annotations and gives the agent insight into output characteristics, though it doesn't discuss limitations or edge cases.

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 well-structured: it front-loads the main purpose, then provides usage instructions, explains the evidence output, and ends with example questions. It is slightly verbose but every sentence contributes useful information, and it maintains a logical flow without redundancy.

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 tool with a single parameter and no output schema, the description adequately explains what is returned (technologies with evidence) and provides example queries. It lacks details on error handling or edge cases (e.g., invalid URLs), but given the simplicity of the tool and the presence of annotations, it is sufficiently complete for an agent to use 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 schema already provides a full description of the 'url' parameter with examples, and schema description coverage is 100%. The description repeats the same instruction ('Give a domain or URL') without adding new semantic details. Since the schema carries the burden, a baseline of 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?

The description explicitly states the tool's purpose: identifying what a website is built with, listing specific technology categories (ecommerce platform, payment processor, CMS, etc.). It also provides example questions that clarify the use case and distinguishes it from siblings by focusing on technology stack detection rather than coverage or AI presence.

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 provides clear usage context by instructing to 'Give a domain or URL' and offering example queries like 'does this company use Stripe or Shopify'. However, it does not explicitly mention when not to use this tool or name alternative tools (e.g., tech_detect_coverage), so it falls short of a 5 on explicit when/when-not guidance.

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