Get Canvas Screenshot

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

Annotations indicate readOnlyHint=true, and the description adds valuable behavioral details: it is fast ('fast screenshot'), does not re-render ('no re-render'), and returns the image inline. No contradictions.

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?

Two efficient sentences with no redundant words. Every sentence provides essential information: action, resource, key behavioral trait, and sibling differentiation.

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 no parameters and no output schema, the description is mostly complete. It covers purpose, performance, and comparison. Potential minor missing detail: what exactly 'current map canvas widget' means, but it is implied.

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. The description adds no parameter information, but with 100% schema coverage and zero parameters, the baseline of 4 is appropriate.

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?

Description uses specific verb 'grab a fast screenshot' and resource 'current map canvas widget', and explicitly distinguishes from sibling 'render_map' by stating it is 'Much faster than render_map' and does not re-render.

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 provides a clear comparison with 'render_map' by stating 'Much faster than render_map', implying this tool is for quick screenshots without re-render. However, it does not explicitly state when not to use or list other alternatives.

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