export_map

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

With no annotations, the description carries the full burden, and it does so reasonably: it discloses the output form (image), the coordinate system (WGS84), and the bbox ordering. It does not mention potential output format details, layer handling, or error behavior, but there is no contradiction or hidden destructive behavior implied.

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?

The description is exceptionally concise: two short sentences, no filler, with the primary behavior and output type stated first and the routing alternative stated second. Every sentence earns its place.

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 tool with 5 parameters, no annotations, and no output schema, the description covers the essential invocation context: what to render, the bbox format, and how it differs from compose_map. The main gap is lack of explanation for the optional layers, width, and height parameters, but schema defaults and names mitigate that gap enough for an agent to make a competent call.

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?

Since schema description coverage is 0%, the description needs to compensate. It usefully explains source and bbox semantics, including coordinate order and units. However, optional parameters like width, height, and layers are not described, so the agent must infer their meaning from their names and schema defaults. This is adequate for required parameters but incomplete for optional ones.

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?

Purpose clarity is excellent. It uses a specific verb ('Render'), names the resource ('one source'), defines the spatial extent ('bbox [minlon,minlat,maxlon,maxlat]'), and states the return type ('image'). It also distinguishes itself from the sibling compose_map by explicitly noting the single-source 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 clear when-to-use guidance: use this tool for a single source in a bbox, and explicitly directs the agent to compose_map for multiple sources. The bbox coordinate order is also given, leaving little ambiguity about how to construct the required parameter.

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