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

Beyond the readOnly/openWorld annotations, the description discloses failure behavior (404 on non-match), billing behavior (failed calls not charged), payment method (x402 on Base/Solana/Arc), price, and data licensing. This is substantive behavioral context an agent needs before invoking a paid external API.

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: purpose first, then output fields, failure behavior, data source, and pricing. Every sentence adds operational value.

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?

An output schema exists, so return-value details are optional, though the description still summarizes key outputs. It covers failure handling, cost, payment requirements, and data source, which is complete for a single-parameter geocoding tool.

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 has 100% description coverage for the single address parameter, so baseline is 3. The description restates that it accepts a one-line US address but adds no format examples or validation details beyond the schema.

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: geocoding a one-line US address via the US Census Bureau. It also names the returned fields, making the tool's scope concrete and distinguishable from generic address parsing.

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 gives clear usage context: it is for one-line US addresses and uses the US Census Bureau. It also explains that non-matching addresses return 404, but it does not compare against sibling tools such as geocode or address_parse.

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