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 behavioral context beyond them: a $0.002 cost per call, the data source, the returned attributes, and explicit accuracy limits. It does not mention rate limits or failure modes for unresolved addresses.

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, both front-loaded: the action and source come first, then outputs/cost/caveats. Every clause carries information the agent cannot get from the structured fields, with no filler.

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?

There is no output schema, so the description proactively enumerates return fields (display names, country/region/type, retrieval time, attribution) plus cost and accuracy boundaries. For a single-parameter lookup tool this is complete enough to call blind.

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?

Only one parameter and schema description coverage is 100%, so the schema already documents 'address' fully. The description repeats the accepted inputs (address, place name, landmark) without adding length, format or ambiguity guidance, so this is baseline-adequate rather than additive.

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 (resolve) and resource (street address, place name or landmark → ranked coordinates) and names the backing service (OpenStreetMap Nominatim). No sibling tool does geocoding, and an agent can tell instantly what this produces.

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 closing sentence delimits the scope: results are 'not legal boundaries, navigation routes or survey-grade coordinates,' which tells the agent when this tool's output is unsuitable. It does not name an alternative tool or a precise triggering condition, so it stops short of explicit when/when-not routing.

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