resolve_postal_codes

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

Annotations already mark this as readOnlyHint=true, so the tool is safe and non-destructive. The description adds that it 'downloads and caches Microsoft's geo-locations file on first use', which is a valuable behavioral detail beyond annotations. No contradictions.

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 that front-load the primary purpose and provide essential behavioral context. No redundant words; every sentence adds 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?

With a known output schema (not shown but present), the description doesn't need to explain return values. It covers the tool's main action and caching behavior. Could mention that it processes multiple codes at once, but this is implied by the array input.

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 description coverage is 100%, with clear parameter descriptions (including example for postal_codes). The description adds context ('Resolve ... to LocationIds') but does not significantly enhance parameter understanding beyond what the schema provides.

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 action ('resolve'), the resource ('ZIP/postal codes'), and the output ('Microsoft LocationIds'). It also specifies the use case ('for location targeting'), which distinguishes it from sibling tools like get_location_targets or add_location_targets.

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 usage (when needing to convert postal codes for targeting) but does not explicitly state when to use this tool over alternatives like get_location_targets or add_location_targets. No exclusions or context about when not to use it.

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