undo

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

With no annotations provided, the description carries the full burden of explaining side effects. It states the basic effect but does not disclose whether undo is limited to a single step, whether it preserves history for redo, whether operations like clear are undoable, or what happens when the history is empty.

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, front-loaded sentence with no redundancy or filler. Every word contributes to identifying the action and target, making it easy for an agent to parse quickly.

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 mutating tool with no annotations and no output schema, this description is too thin. It omits important operational context such as the undo history model, the interaction with redo and clear, and the behavior when there is nothing to undo. An agent could easily call it incorrectly or misinterpret its scope.

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 already fully documents the 'canvas' parameter with 100% coverage and a default value. The description adds no extra parameter-level meaning, format details, or dependency conditions, so it meets but does not exceed the baseline for schema-covered parameters.

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 the action ('Undo') and the resource ('the last drawing operation on a canvas'), and it is immediately distinguishable from siblings like redo. However, it does not explicitly contrast itself with redo or explain what counts as a drawing operation.

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 using this tool to revert the most recent drawing action, but provides no explicit guidance on when to choose undo versus redo, how multiple undos behave, or what happens if no drawing operation exists. The sibling list includes redo, so a selection rule would be valuable.

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