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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world. The description adds genuinely new behavioral facts: coordinates are rounded to about 1 km and nothing is stored, which tells the agent the resolution is lossy and privacy-safe.

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?

A single dense sentence that front-loads accepted inputs, then the output, then the workflow constraint. No filler and nothing repeated from the schema or 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?

With no output schema, the description steps in to say what comes back (a point and radius), how precise it is, and that nothing persists. Combined with the routing to find_pets, an agent has everything needed to call this 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% for the single 'near' parameter, so baseline is 3. The description earns an extra point by clarifying that Taiwan place names are accepted in 'any language', a constraint the schema does not state, and by describing what the parameter resolves to.

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+resource ('turn ... into the point and radius') and enumerates the accepted input forms (US ZIP, lat,lon, Taiwan county/township). It also names the downstream sibling find_pets, so an agent can place this tool precisely in the workflow.

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 makes the usage context clear: resolve first, then 'confirm with the person before searching', with find_pets as the consumer. It stops short of stating when-not to use it or what to do on failure, but the pre-search sequencing is unambiguous.

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