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

Annotations already cover readOnlyHint, idempotentHint, and destructiveHint, so the description is not required to restate safety. It adds the behavioral note that 'Demo mode allows selected sample domains,' which hints at restricted availability but is vague about what demo mode entails, who it applies to, or when it activates. This is minor added context beyond annotations but lacks clarity.

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 a single concise sentence with the core action front-loaded. The 'Demo mode' clause adds a behavioral footnote but is not verbose or redundant. It earns its place by informing about a limitation, though it could be worded more transparently.

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 one-parameter, read-only lookup tool with rich annotations, the description is nearly sufficient but leaves gaps. The term 'Demo mode' is unexplained, and the output shape of a 'company profile' is not described, which could matter given there is no output schema. The domain input format is covered by the schema, but the overall tool behavior is only partially contextualized.

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%, with the parameter 'domain' described as 'Company domain or URL.' The description echoes this by using 'by domain' and 'sample domains' but does not add format examples, normalization rules, or edge-case handling. Baseline 3 is appropriate because the schema already documents the parameter sufficiently.

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 states a specific verb and resource ('Return a company profile by domain'), making the tool's primary function clear. It does not explicitly distinguish itself from siblings like company_enrich or company_lookup_auto, but the domain-based lookup is evident from the name and phrasing. The mention of 'Demo mode' introduces a slightly ambiguous secondary detail but does not obscure the core purpose.

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?

No guidance is given about when to use this tool versus alternatives such as company_enrich, company_lookup_auto, or company_search. The phrase 'by domain' implies the input type, but there is no explicit context for selecting this tool over siblings, nor any exclusion or preference statement. The 'Demo mode' reference is not actionable usage guidance.

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