get_map_image

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

With no annotations, the description carries the behavior disclosure burden. It states the output is a PNG image URL, clarifies the required coordinate format, and warns about the MapServer-only constraint. It could say more about errors, auth, or side effects, but 'render and return image URL' is reasonably transparent for a read-oriented mapping operation.

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 four concise sentences with no filler. The main behavior is frontloaded, followed by intended use, required input, and a key compatibility warning. Every sentence contributes.

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?

Given there is no output schema, the description helpfully states the return value is an image URL (href). It also covers required bbox format and service_path constraints. It lacks only minor details such as error behavior for invalid bboxes or missing MapServer services, but the tool is simple enough that the description is sufficiently complete.

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 50%, covering only bbox and service_path. The description reinforces those two parameters and adds the WGS84 bbox format context, but it does not mention width or height. However, width and height are already well constrained by schema defaults and min/max bounds, so the gap is minor.

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 clearly states a specific action: render a PNG map image from a MapServer service and return its URL. It also distinguishes itself from sibling query tools by framing it as 'a quick visual of a bounding box' rather than a data query or feature operation.

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?

It says when to use it: for a quick visual of a bounding box. It also gives a clear when-not: FeatureServers do not expose MapServer endpoints. However, it does not explicitly name an alternative sibling tool to use instead for FeatureServers.

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