precise_annotate

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

With no annotations provided, the description carries the behavioral disclosure burden. It does disclose core behavior: exact coordinate placement, no auto-positioning, and type-specific coordinate semantics. However, it does not describe side effects such as whether annotations persist, whether existing annotations are affected, or how invalid or out-of-bounds coordinates are handled.

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 well-organized, front-loaded with the key behavioral promise, and uses brief coordinate rules followed by concrete examples. Every sentence serves a purpose, and the examples are clear and actionable without unnecessary verbosity.

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?

For a 13-parameter tool with a full schema and an output schema, the description is largely complete: it explains coordinate conventions, gives usage examples, and covers all major annotation types. The main gap is the lack of explicit guidance on when to use this tool versus the many similar sibling tools, and it assumes the agent knows how to supply image_id from the examples.

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 coverage is 100%, so the baseline is 3. The description adds meaningful value by explaining coordinate semantics per annotation type: top-left for box, center for circle, start for text, and x2/y2 for arrows/lines. The examples further clarify parameter usage, exceeding what the schema alone provides.

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 identifies the tool as a pixel-perfect annotation tool with a specific verb and resource: it places annotations at exact pixel coordinates. It distinguishes itself from convenience/auto-positioning alternatives by stating 'no anchor adjustments, no auto-positioning', though it does not explicitly name any sibling tool.

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 implies when to use the tool: when exact pixel placement is required, and not when auto-positioning or anchor adjustments are desired. However, it provides no explicit guidance or clear alternatives, despite many overlapping sibling tools like add_box, add_arrow, add_text, and annotate.

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