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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds valuable context: it is a 'Premium API' with a specific cost ($0.25 USDC via x402), and lists the exact return fields. This goes beyond the annotations without contradicting them.

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?

Two sentences, purpose front-loaded, with the cost and premium status at the end. The first sentence is long due to the data-field list, but each item is informative and not redundant. It is appropriately concise for the content.

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 single-parameter tool with no output schema, the description is complete: it states what is returned (the full field list), the cost, and the geographic scope. An agent can call it correctly with the provided example address and know what to expect in the response.

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% for the single 'address' parameter, which already includes a description ('US property street address') and an example. The description's 'for any US property address' restates the same scope without adding new semantics. Baseline 3 applies when the schema does the heavy lifting.

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 opens with a specific verb ('Retrieve') and resource ('commercial building profile'), and scopes it to 'any US property address'. It enumerates the specific data points returned, clearly distinguishing it from sibling tools like address matching or business info. The purpose is unambiguous.

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 it—when building-level data is needed for a US address—but does not explicitly name alternatives or state when not to use it. With a large sibling list, explicit routing would be helpful, but the purpose is clear enough that an agent can infer usage.

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