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

Annotations already provide readOnlyHint/openWorldHint/idempotentHint/destructiveHint. The description adds useful behavioral context: MIT licence, no auth, no upstream cost, and 'returns elevation in metres with dataset name.' It does not discuss rate limits or out-of-region behavior, but the annotation coverage lowers the burden.

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 short sentences, front-loaded with the core purpose, then return format, dataset guidance, and access constraints. Each sentence serves a purpose, though the licence/auth/cost sentence is a slight extra rather than essential to invoking the 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?

The description covers purpose, dataset options, coverage limits, return value, and access constraints. With a rich output schema and annotations, the main remaining gap is explicit error handling outside US/Europe coverage, but the 'continental US only' and 'Europe only' markers imply the limitation.

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%, so the baseline is 3. The description adds meaning beyond the schema by advising when to use ned10m vs eudem25m, which helps an agent choose the right dataset parameter. It does not need to restate lat/lon or interpolation details already in the schema.

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 opens with a specific verb and resource: 'Get high-resolution elevation for a single coordinate' using regional datasets. It names the two datasets and their regional scopes, which distinguishes this from sibling batch/ocean/point elevation tools by coverage and single-point scope.

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 gives concrete guidance for choosing between datasets ('Use ned10m for US urban/terrain analysis and eudem25m for European...higher accuracy than SRTM') and states regional restrictions. It does not explicitly name alternative tools for global or multi-point queries, but the context is clear enough for dataset selection.

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