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

Annotations already declare readOnly, idempotent, open-world, non-destructive behavior, so the burden is low. The description adds genuinely useful context beyond them: the primary source (Copernicus GLO-30), the Open Elevation fallback (signaling possible quality variance), and that the datum and accuracy come back with the value.

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 front-loaded sentence that packs units, source stack, and return qualifiers with zero filler. Nothing can be removed without losing information.

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 two-parameter point-query with a full output schema and complete annotations, the description covers what the value means and its provenance. The only gap is the absence of any statement about coverage or limitations (e.g., ocean/no-data points), which would matter for an open-world terrain 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?

Schema coverage is 100%, with both latitude and longitude documented as WGS84 degrees including min/max bounds in the schema. The description adds no further parameter semantics, so the baseline 3 applies.

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 resource (ground elevation) with units (metres), the data sources used, and what accompanies the value (vertical datum, accuracy). It is clearly distinct from the geocoding/routing siblings, though it never explicitly contrasts itself with a sibling like location_report that might also carry elevation.

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?

There is no when-to-use or when-not-to-use guidance, and no alternatives are named. The agent must infer from the name and the lat/lon inputs alone that this is the single-point elevation lookup versus any composite tool.

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