Get Canvas Screenshot

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

Annotations declare readOnlyHint=true, so the tool is known to be non-destructive. The description adds behavioral context: it returns the image inline, is fast, and avoids re-render. This goes beyond what annotations provide, though no additional details about edge cases or limitations are given.

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 extremely concise, with two sentences that immediately convey the tool's purpose, speed advantage, and output format. No superfluous words.

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 absence of parameters and output schema, and the presence of annotations, the description covers the key aspects: what the tool does, its main benefit, and the return type. It is complete enough for a simple screenshot tool, though one might wish for mention of potential failures (e.g., no active canvas).

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 parameter information. Per the guidelines, zero parameters yields a baseline of 4.

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 'grab' and resource 'screenshot of current map canvas widget', and explicitly distinguishes it from the sibling tool render_map by emphasizing it is faster 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 clear context for when to use this tool: for a fast screenshot without re-rendering. It points to render_map as the alternative for full rendering, but does not explicitly state when not to use it or mention prerequisites.

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