edit_undo

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

With no annotations, the description carries the full behavioral burden. It does disclose an important behavior: the tool fails cleanly when there is nothing to undo, which is useful for an agent deciding to call it. However, it does not explain what happens on success, whether multiple undos are supported, or how this interacts with project state and history.

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 two short sentences with no filler. The core action is stated first, and the failure behavior is a meaningful second sentence. Every word earns its place.

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 zero-parameter, low-complexity tool, the description covers the main action and a key edge case. It lacks detail on return values or the scope of an undo, but those are relatively minor given the simplicity of the operation and the availability of sibling edit_redo for context.

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 has zero parameters, so the schema is trivially complete and the description has no parameter semantics to convey. Per the baseline for zero-parameter tools, this dimension deserves a solid score.

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 uses a clear verb ('Undo') and a specific resource ('the last edit'), making the tool's purpose immediately understandable. It does not explicitly differentiate from sibling edit_redo, though the opposite meaning is implicitly clear from the name and wording.

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 by stating what the tool does, but it does not explicitly say when to prefer this over alternatives or mention any prerequisites. The note about failing cleanly provides a small amount of situational guidance, but there is no explicit when-to-use or when-not-to-use framing.

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