undo_last

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

The readOnlyHint=false annotation indicates mutation, and the description adds that it operates on the Unity Undo stack, distinguishing it from direct object changes. However, it does not disclose side effects, failure conditions (e.g., insufficient undo history), or whether it affects only scene state or also other editor state. Given the sparse annotations, the description provides some but not rich behavioral context.

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 sentence that is front-loaded with the action, includes the key parameter ('N'), and provides the default. No unnecessary words or repetition.

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 simple undo tool with no output schema and minimal parameters, the description covers the essential behavior and default. It could be improved by noting limitations or what exactly gets reverted, but it is sufficiently complete for basic use.

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 input schema has no parameters, so the baseline is 4. The description adds semantic meaning by explaining the 'N' concept and its default value, which is useful even though the schema does not expose a parameter for it.

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 states a specific action ('Undo') applied to a specific resource ('the last N AI turns in the Unity Undo stack') and includes the default value. It is distinct from sibling tools like set_property or delete_object, which modify or create rather than revert.

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 usage: it should be used when the agent needs to revert its own recent AI-driven changes. It does not explicitly mention when not to use it or name alternative tools, but the context is clear enough for selection.

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