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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered. The description adds real value beyond that: it discloses the return shape (one block per input address containing matched address, coordinates, and county/tract GEOIDs) and the 10-item ceiling, which tells the agent how failures/successes map back to inputs.

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 what the tool does and how many rows it accepts, then the return contract, then the scale boundary. No filler and nothing repeated from the annotations.

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?

No output schema exists, but the description supplies the return structure itself, and the annotations cover safety and idempotency. For a one-parameter batch tool, an agent has everything needed to call it correctly and interpret 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?

With 100% schema coverage and a single parameter, the baseline is 3; the description adds two constraints not spelled out in the schema's short text — that addresses must be US and formatted as one-line strings — plus the practical batch-size intent behind maxItems: 10.

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 (geocode), a resource (US addresses), and a hard scope (up to 10, one-line, in a single call). The final sentence contrasts small ad-hoc batches against the 10k-row Census batch file API, which lets an agent separate this tool from the single-address geocode siblings without opening any 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?

Explicitly says when to use it (small ad-hoc batches) and when not to (large jobs, which belong to the Census batch file API). The only gap is that the named alternative is an external API rather than the sibling MCP tools geocode_address / geocode_coordinates, so it doesn't route the agent among invocable tools.

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