ass_drawing_bbox

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

With no annotations, the description carries the full burden and does reasonably well: it discloses the coordinate space (drawing's own scale space, \p level) and the non-obvious semantic that the box is the control polygon box including Bézier/B-spline handles, matching VSFilter/Aegisub. It does not cover error cases or how the drawing is resolved, so it falls short of full disclosure.

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?

Front-loaded with the purpose, then relevant coordinate-space caveat, then return shape. Slightly redundant (the centre/center and size/bbox duplication), but every sentence is short and useful.

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?

An output schema exists, so listing return fields is optional reinforcement rather than required content. The real gap is that a 3-parameter tool with zero schema coverage and no annotations leaves the agent unable to know which selector to pass or how the drawing is located.

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 description coverage is 0% and all three parameters (text, index, doc_id) are undocumented in both schema and description. The description never explains how these selectors interact or which one takes precedence, only mentioning doc_id/index incidentally as return fields.

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 first line states a specific computed resource — 'Bounding box / size / centre of a drawing' — with a clear implicit verb (compute/return). This is easily distinguished from siblings like ass_drawing_info, ass_get_drawing, or ass_transform_drawing, which mutate or describe rather than measure.

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?

There is no statement of when to call this versus alternatives such as ass_drawing_info or ass_drawing_to_svg. The VSFilter/Aegisub note explains what the result means for positioning, but not the condition that selects this tool. No exclusions or prerequisites are given.

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