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

Annotations already mark the tool as readOnlyHint=true, idempotentHint=true, and destructiveHint=false. The description adds value by revealing that no request-time network call is needed (suggesting cached or offline data) and that results are 'population-ranked' and 'bounded'. This discloses behavioral traits beyond what annotations provide, making the tool's operational context clearer.

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 a single sentence that packs significant detail (input, output fields, ordering, no network call) without being overly verbose. It is well front-loaded with the main action. However, it could be slightly more structured by splitting into smaller sentences for readability, but overall it is efficient and earns its place.

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?

Given the presence of an output schema and rich annotations, the description provides a good overview of the tool's inputs, outputs, and key behavioral traits. Minor missing detail: it does not mention that the tool returns multiple candidates (implied by 'population-ranked' but not explicit). However, the limit parameter in the schema covers this, so the description is sufficiently complete for an agent to use correctly.

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%, so baseline is 3. The description does not add any additional meaning beyond the schema; it only mentions the input is a 'city or locality name' but does not describe the 'limit' parameter or provide further semantics. The schema itself already describes both parameters well, so the description adds no extra value for parameter understanding.

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 tool resolves a global city or locality name into detailed geographic data (coordinates, country, region, population, timezone, etc.). It uses a specific verb ('resolve') and resource ('city or locality name'), and distinguishes itself from sibling tools like data.us-address-geocode by specifying 'global' and 'without a request-time network call'.

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 the tool is for global city/locality names but does not explicitly state when to use it over alternatives. It lacks clear 'when to use' or 'when not to use' guidance. The schema parameter description for 'place' provides a limitation (not for street addresses), but the tool description itself offers no usage direction, leaving the agent to infer context.

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