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

No annotations are provided, so the description carries the full behavioral burden. It usefully discloses FREE, GSI DEM as the source, meters as the unit, and Japan-only coverage, but omits coordinate reference/order, accuracy, rate limits, and response shape.

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 short sentence with no filler; 'FREE.' front-loads useful cost information and the remaining text is dense. The brevity contributes to gaps elsewhere, but as a conciseness measure it is strong.

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 two-parameter lookup, it covers units, source, and geography. However, with no annotations, no output schema, and 0% schema description coverage, it lacks enough parameter and return context for fully confident invocation.

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 0% and there are no per-parameter descriptions. The description only echoes 'lat/lon' and adds no coordinate format, ordering, datum, or bounds for the two required parameters.

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 exactly what is returned (Elevation in meters), for what input (one lat/lon), and the regional/data-source scope (Japan via GSI DEM). The 'one lat/lon' wording also implicitly separates it from the batch and path-oriented 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?

No explicit when-to-use, when-not-to-use, or named alternative is provided. The single-point scope implies it is for one coordinate while batch_elevation handles many, but the agent must infer that routing.

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