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

Annotations already declare readOnlyHint=true and idempotentHint=true, so the safety profile is known. The description adds concrete behavioral output (including timezone) and an example, with 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?

Three front-loaded sentences: purpose, usage condition, example. Every sentence earns its place; no fluff.

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?

For a simple, read-only tool with an output schema, the description conveys purpose, usage, and a worked example. It does not explicitly correct the misleading 'location' note in the schema or address edge cases, so it falls just short of full completeness.

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?

The schema already covers both parameters with ranges and descriptions (100% coverage), so baseline is 3. The description adds a concrete example mapping lat/lon to a result, though the schema's lat description misleadingly mentions a 'location' string that additionalProperties=false contradicts.

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 ('coordinates') and enumerates the output categories (city, state, county, timezone). The example concretely differentiates it from forward geocoding (search_locations) and weather-focused siblings.

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 instruction 'Use when you have lat/lon but need a display name or the local timezone' provides an explicit condition for selection. It does not name sibling alternatives or exclusions, but the condition is sufficiently clear.

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