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

Annotations already declare readOnly/idempotent/openWorld, so safety is covered; the description adds the result cap ('up to 20 places') and enumerates the returned fields, which is real behavioral context beyond the annotations. It doesn't mention rate limits or pagination, keeping it short of a 5.

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?

Four sentences, front-loaded with the core selection rule, then alternative routing, then return shape, then the handoff. No filler and no repetition of the tool name.

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 search tool with no output schema, the description supplies return-field detail and the downstream chain to places_details, which is what an agent needs to plan a call. It stops short of covering the two undocumented parameters or pagination behavior.

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 75% and the schema already documents query, radius, lat/lng, included_type and max_result_count. The description adds only the max=20 constraint and positional bias intent, which is roughly baseline for this coverage level. field_mask and language_code remain undocumented in both places.

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?

Opens with a specific verb+resource ('Find places by free text') and immediately disambiguates the sibling by naming places_nearby and the exact condition that selects it ('only when you already have exact coordinates'). An agent can route between the two tools without opening either schema.

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?

Explicitly declares itself the 'Default choice for finding places' and gives the exclusion rule for the alternative tool. It also hands off to places_details for phone/website, so the multi-step workflow is covered.

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