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

Goes well beyond the readOnly/openWorld annotations: discloses the exact return shape, hard caps (up to 5 signals, 8 sources), cost (14 credits per successful call, with the credit-to-CAD conversion), and the billing rule that schema-invalid input is rejected before charge. That cost and failure-mode context is exactly what an agent needs before spending credits.

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?

Three tight sentences, front-loaded with purpose and return shape, then cost and rejection behavior. The inline return-type literal earns its space by eliminating the need for an output schema; 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?

With one required parameter, no output schema, and only two annotations, the description fills every real gap: return contents, result caps, cost, and pre-billing validation. Nothing an agent needs in order to call this correctly or budget for it 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?

Schema coverage is 100%, and the schema already documents the domain format, length bounds, and the rejection of IP literals and private suffixes. The description reinforces the 'public' constraint but adds no syntax or format detail beyond what the structured field states. Baseline 3 applies since the schema carries the parameter burden.

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+resource (company profile enrichment) and enumerates the returned fields: name, description, industry, signals, sources. It also bounds the scope explicitly with 'Organisations only, never people', which distinguishes it from a generic entity/search tool. An agent can tell instantly what it produces without opening the schema.

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?

Provides a clear when-not ('Organisations only, never people') and a required input contract (public domain, IP literals and private suffixes refused). It doesn't route to any named sibling (e.g. enrich-url, web-search, web-extract) for overlapping needs, so the alternative-selection guidance is incomplete.

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