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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false. The description adds context: it uses the Google Maps Elevation API, supports batch queries via pipe-separated locations, and returns elevation in meters. This adds meaningful behavioral information beyond what annotations provide, though no details on API limits or error handling.

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?

The description is two sentences, each serving a purpose: first sentence states the core function and data type, second explains the input format. It is front-loaded with key terms and contains no fluff. Ideal conciseness for an agent tool.

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?

Given the complexity (2 parameters, simple return value), annotations (safe read), and presence of output schema, the description covers the essential: purpose, input format, and data source. No missing information for an agent to correctly invoke the tool.

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 input schema fully describes both parameters (100% coverage), but the description adds value by explaining the format: 'Pipe-separated "lat,lng" pairs' and mentioning batch queries. This helps the agent understand the exact syntax required for the 'locations' parameter, going beyond the schema's generic description.

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 tool returns elevation in meters for lat/lng pairs via Google Maps Elevation API, using terms like 'elevation at [coords]' and 'altitude / height above sea level'. It distinguishes itself from sibling tools like maps_directions, maps_geocode, etc., by specifying the unique API and data type.

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 for elevation queries (e.g., 'elevation in meters for one or more lat/lng pairs') but provides no explicit guidance on when to use this tool versus alternatives, nor does it mention when not to use it. The context from sibling names suggests differentiation, but the description itself lacks direct usage guidance.

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