draw_numbered_callouts

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

With no annotations provided, the description must fully disclose behavioral traits, but it only says 'Draw numbered callout circles'. It does not mention if the image is modified in-place, required permissions, side effects, or that it is a wrapper (which may imply limited functionality).

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?

While the description is short (one sentence), it is under-specified for a tool with 7 parameters. Important information is omitted, so brevity here sacrifices usefulness, making it less than concise in the sense of carrying necessary information.

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 annotations and an output schema, and a tool with 7 parameters, the description fails to provide a complete understanding. It does not describe return behavior, the meaning of 'normalized', or how 'callouts' are structured, making it inadequate for an agent to use correctly.

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?

The input schema has 0% schema description coverage, and the description adds no explanation of the parameters. 'callouts' is an array of objects with no constraints, but the description does not clarify its structure or expected format, leaving the agent with no guidance beyond parameter names and types.

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 action ('Draw numbered callout circles') and the resource ('on an image'), and explicitly distinguishes itself as a convenience wrapper around 'annotate', implying a specific use case for numbered callouts compared to sibling tools like draw_bounding_box.

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 hints that this tool is a simplified version of 'annotate', suggesting when to use it (for numbered callouts) versus the more general 'annotate'. However, it does not provide explicit guidance on when not to use it or compare to other siblings like detect_text_regions.

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