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

With no annotations provided, the description carries the full burden of behavioral disclosure. It transparently explains conditional fields (phone, website, etc. only for paid plans; description only for Business/Premium) and the inclusion of quote_request_url. This gives the agent a clear picture of what data to expect based on plan type, which is valuable context.

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 two sentences, front-loaded with the primary purpose. The second sentence is dense but necessary to disclose conditional fields. It is concise without being under-specified, though the long second sentence could be slightly reorganized for readability.

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 comparison tool with a single parameter and no output schema, the description adequately explains the parameter constraints, the fields returned, and conditional availability. It does not explicitly describe the output format, but that is not critical for invocation. The description is sufficient for an agent to understand what the tool returns and how to use it.

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 has a description for business_ids ('Array of business UUIDs to compare') and enforces maxItems=5. The tool description adds context about what the comparison involves but does not add new parameter-specific semantics beyond what the schema provides. Baseline 3 is appropriate given 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 verb 'Compare' and the resource 'businesses', and specifies the scope (up to 5) and the fields included. It distinguishes itself from siblings like get_business (single) and search_businesses (listing) by its explicit comparative purpose and the mention of specific data points like BezalRank and claim status.

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 usage for comparing multiple businesses but does not explicitly state when to use this tool over alternatives like get_business or search_businesses. It mentions the limit of 5, which is a constraint, but no explicit exclusions or routing guidance is provided.

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