undo

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

With no annotations provided, the description must carry the full burden of behavioral disclosure, but it only states the obvious action. It does not mention what happens when the undo stack is empty, whether undo reverts only the most recent operation or can be called repeatedly to step back further, or how errors are reported. The phrase 'most recent operation' gives a hint of scope, but many behavioral details are left undocumented.

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 a single, compact sentence with zero filler. It front-loads the system context ('Blender's undo system') and immediately states the action. No unnecessary information is included, making it an appropriately sized definition.

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 tool's trivial complexity (no parameters, clear action, output schema present), the description is nearly sufficient for an agent to invoke it correctly. The only missing context is edge-case behavior (e.g., empty undo stack), but these are minor and unlikely to cause incorrect invocation. The presence of an output schema relieves the description from explaining return values.

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 tool takes no parameters, and the input schema shows an empty object (100% schema coverage, trivially). The description therefore has no parameter meanings to clarify, and the baseline score of 4 applies. There is nothing missing on the parameter front.

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 states a specific verb ('undo') and a clear resource ('Blender's undo system'), making the tool's function unmistakable. It also distinguishes the tool from its siblings, which are pose, rig, and viewport operations, since 'undo' is a general state-reversal action rather than a domain-specific edit.

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 the obvious use case (call after a previous operation to reverse it) but gives no explicit guidance on when not to use it or how it compares to alternatives like reset_pose or set_pose_batch. The usage context is inferable from the name and description, but the tool does not articulate edge cases such as multiple undo steps or interactions with other Blender operations.

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