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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so safety is covered. The description adds real value beyond that: it discloses the return shape ('ranked address/place suggestions with coordinates') and the optional proximity-biasing behavior, which annotations do not convey. It stops short of rate limits or quota details.

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 short sentences, front-loaded with the purpose and return value, followed by the optional bias and a compact example. The example slightly duplicates the schema's examples block but is well-integrated and wastes little space.

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 correctly carries the return-value burden (ranked suggestions with coordinates). Combined with full annotation coverage and 100% schema description coverage, an agent has what it needs to call the tool; only alternative-routing guidance is missing.

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%, so every parameter (near, limit, query, _apiKey) is already documented in the schema with types and examples. The description echoes the proximity-bias concept and provides an inline call example but adds no syntax or constraints beyond the schema, so baseline 3 is appropriate.

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 (autocomplete) and resource (address/place) with the key differentiator 'from partial text', which separates it from the sibling geocode tools that resolve full addresses. It does not explicitly name radar_geocode/radar_reverse_geocode as alternatives, so full sibling differentiation is left to inference.

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 (partial text, optional proximity bias) and gives a concrete example, so an agent can infer when it applies. However, it never states when NOT to use it or names the geocode sibling it should fall back to for full addresses, leaving routing to inference.

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