builtwith_lookup

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

With no annotations provided, the description carries the full behavioral disclosure burden. It usefully reveals that the tool relies on the free BuiltWith API and requires no API key, which is meaningful operational context. It does not disclose rate limits, failure modes, data freshness, or whether the 'any website' claim has constraints, so transparency is only partial.

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 compact and front-loaded: the first sentence states the core purpose, and the second adds essential API/auth context without waste. Every sentence earns its place, and there is no redundant repetition of the tool name or schema details.

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 simple two-parameter lookup tool with complete schema descriptions and an output schema present, the description is largely complete. It covers the external API and authentication requirement, while the return format is presumably handled by the output schema. Minor omissions like rate limits or explicit sibling differentiation prevent a perfect score.

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%, so the schema already documents both parameters clearly: 'domain' and 'format'. The description adds context about what the analysis covers but does not add meaning beyond the schema for either parameter; therefore, the baseline score 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 uses a specific, informative verb ('Detect') with a clear resource ('technology stack of any website') and enumerates the covered categories (CMS, analytics, ads, frameworks, hosting). It is distinct from the sibling tools in function, though it does not explicitly name a competing tool such as semrush_domain_overview to draw the boundary.

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 implies when to use the tool: whenever you need to identify a website's CMS, analytics, ads, frameworks, or hosting. However, it does not explicitly describe when not to use it or recommend any sibling alternative, so the usage guidance remains implicit rather than fully directive.

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