autocad_create_arc

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

Annotations already declare readOnly=false, destructive=false, idempotent=false and openWorld=false, so the safety profile is covered. The description adds useful behavior detail — angles are in DEGREES with 0 = east/+X and CCW positive, and layer defaults to '0' — plus the response shape, but omits prerequisites such as requiring an active document and whether an out-of-range/degenerate radius errors out.

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 operation in one sentence, then a compact Args/Returns block; nothing is padded. The Returns line is somewhat redundant given an output schema exists, but it is short and harmless.

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 single-struct mutation tool with full annotations and an output schema, the description supplies the geometry conventions, the default layer, and the return shape — everything needed to invoke it correctly. Return-value explanation is not required since an output schema exists, so its presence is a bonus, not a gap-filler.

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?

Measured schema coverage is 0% (the single top-level 'params' field is a bare $ref), so the description has to carry the parameter burden — and it does, enumerating center, radius (>0), start_angle, end_angle with unit conventions, and the default layer. It mirrors the nested schema's own field descriptions rather than adding syntax beyond them, which keeps it at 4 rather than 5.

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?

States a specific verb and resource — "Draw an arc" — and adds the defining geometric semantics (counter-clockwise from start angle to end angle), so an agent knows exactly what geometry will be produced. It does not explicitly differentiate itself from siblings like autocad_create_circle or autocad_create_polyline, but those are distinct enough by name that the gap is minor.

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 when-to-use guidance at all: nothing about prerequisites (an open/initialized drawing), when an arc is preferable to a polyline or boundary, or what happens if no document is active. The description only explains the mechanics of the call, not the context for making it.

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