undo

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

With no annotations, the description carries the burden. It adds the useful behavioral detail of 'Single-step undo,' but does not disclose what happens when there is no previous operation, whether the undo is itself reversible, or any side effects. These gaps keep it at a minimum viable level.

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, front-loaded with the primary action and a clarifying detail. Every word is meaningful, making it appropriately concise and well-structured.

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?

The tool is simple with one parameter and no output schema. The description covers the core purpose but leaves out edge-case behavior (e.g., empty undo stack) and return value expectations. Given the simplicity, this is adequate but not thorough.

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?

Schema coverage is 100% with a simple 'Canvas ID' property. The description does not add any meaning beyond the schema, and the schema description is minimal. The baseline for high coverage is 3, and there's no additional semantic value provided.

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 specific action ('Revert the last drawing operation') and the resource ('a canvas'), and further clarifies the single-step nature. This distinguishes it from other tools by explicitly scoping to drawing operations.

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 provides clear context for when to use it: after a drawing operation to revert it. It also implicitly excludes multi-step undo with 'Single-step undo,' but does not explicitly mention alternatives or when not to use it, so it stops short of a 5.

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