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

With no annotations, the description carries the load and does a lot: it discloses the required GISGP Lite plan/api_key or Bearer auth, per-source area caps that will constrain calls, and the two return shapes (GeoJSON+stats vs {ok, filename, data_base64}/{ok, download_url}). It omits error/failure behavior and whether a call consumes pass quota.

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?

Very dense with almost no filler — every clause adds a constraint, allowed value, or return shape. It loses a point for front-loading pricing/auth framing before the actual operation and being a single run-on block rather than structured.

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 tool with zero schema descriptions and no annotations, the description supplies the missing auth, area limits, enumerations and return shapes needed to call it correctly. The only real hole is major_every, whose effect on output is never mentioned, and there is no note on failure modes.

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%, so the description must compensate, and it does for 7 of 9 params: bbox ordering [west, south, east, north] in degrees, polygon as GeoJSON, source values, interval semantics (omit for automatic), units, format enum, and crs as an EPSG code defaulting to the UTM zone. Only major_every and the api_key mechanics are left thin, which keeps it below 5.

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 verb+resource (generate contour lines) and immediately scopes it: from a bbox or polygon, from Copernicus 30 m or USGS 10 m, in a chosen interval/units/format. No sibling tool in the list produces contours, and the description makes the operation unmistakable.

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 among parameter values — cop30 for worldwide coverage up to 100 km², usgs10 for the US up to 25 km² — which tells the agent which mode to pick for a given area. It does not explicitly exclude or route against sibling tools (e.g. get_terrain_profile, geojson_to_dxf), so it stops short of full when/when-not guidance.

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