Get Canvas Extent

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

The readOnlyHint annotation already indicates safety. The description adds context that the tool returns both the map canvas extent and CRS, which is beyond what the annotation provides. No additional behavioral traits are needed, and there is no contradiction.

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 a single, front-loaded sentence with no wasted words. It efficiently communicates the purpose.

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 the tool's simplicity (no parameters, read-only, with an output schema), the description is complete. The presence of an output schema means return values need not be explained in the description. It covers the essential information.

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?

There are no parameters, so the description does not need to add meaning beyond the schema. The schema has 100% coverage, and the description implies the output is the extent and CRS, which is sufficient.

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 the verb 'Get' and the resource 'current map canvas extent and CRS', distinguishing it from siblings like get_canvas_scale (extent vs scale) and set_canvas_extent (read vs write). It is specific to the canvas, not layers or project.

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 tool has no parameters and is read-only, so agents can infer it's safe to call anytime. However, the description lacks explicit guidance on when to use this over alternatives like get_project_info for CRS or get_layer_extent for layer extents. No exclusions or alternative tools are mentioned.

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