cad_object

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

Annotations already indicate destructiveHint=true, and the description adds that cad_object 'edits the current document's geometry,' making the mutation scope explicit. It also discloses that the boolean action 'requires the optional boolean extra,' which is essential operational context beyond the schema. No contradiction with annotations exists.

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 structured with a lead summary, bullet-like action breakdown, and a dedicated 'When not to use' section. Despite being longer than average, every sentence serves a purpose and the layout is scannable for an agent needing to dispatch by action. No fluff or repetition beyond the minor bilingual restatement.

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?

The tool has 8 distinct action variants and an aggregate schema, yet the description covers each action's purpose, key parameters, and return behavior for create. It also addresses optional prerequisites (boolean extra) and sibling tool boundaries, making it fully adequate for selection and invocation even with the output schema present.

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?

Though schema description coverage is 100%, the description adds critical semantic detail: it lists the allowed create types (line, circle, arc, etc.), specifies that transform uses a '4x4 matrix (column-major, translation in the fourth column)', and notes that create returns 'the new object_id and bounding box'. These enrich the bare schema parameter descriptions.

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 opens with 'Create, read, update, delete, copy, transform, list or boolean objects,' a specific verb+resource statement that also enumerates the distinct actions. Each action is further elaborated with its target (e.g., 'add an entity by type', 'apply a 4x4 matrix'), and the tool is explicitly differentiated from siblings like cad_file, cad_json, cad_measure, and cad_validate.

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?

A 'When not to use' section explicitly names alternative tools (cad_file for import/export, cad_json for JSON round-trips, cad_measure for measurements, cad_validate for validation) and clarifies that cad_object edits the current document's geometry. This gives the agent both positive and negative usage signals.

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