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

With no annotations, the description carries the full burden and does it well: it discloses that a paid GISGP Lite account and api_key (or Bearer token) are required, and states hard area limits per source (100 km² / 25 km²). It omits rate limits and failure behavior, keeping it out of top marks.

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?

Dense but nearly every clause carries information the agent needs (auth, sources, limits, formats, returns). The pricing detail is front-loaded ahead of the actual purpose statement, which is slightly backwards ordering, but the content is economical.

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 9-parameter, annotation-free tool this covers auth, source/area constraints, geometry inputs, formatting, and output shape. An output schema exists so return values need not be explained, and the only real hole is the undocumented major_every parameter.

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% across 9 params, so the description must compensate, and it documents bbox ordering, polygon, source values, units values, interval semantics, the full format enum, and crs default (UTM zone). Only 'major_every' goes unexplained.

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?

Names a concrete output (contour lines) with an explicit verb-like action, and states the two accepted geometries (bbox or GeoJSON polygon) plus the two elevation sources. It is unmistakably distinct from siblings like get_elevation or get_terrain_profile, which return point/profile data rather than contour geometry.

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?

Gives clear selection criteria between sources: cop30 is 'worldwide, up to 100 km² per box' while usgs10 is 'US, up to 25 km²', which lets an agent pick correctly. It does not, however, state when to prefer this tool over the elevation/terrain siblings, so it stops short of full alternative routing.

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