undo

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

Annotations already declare readOnlyHint=false and destructiveHint=false, indicating a mutating but non-destructive operation. The description adds meaningful behavior beyond that: it returns whether anything was undone and the resulting { canUndo, canRedo } state. This helps the agent understand no-op situations and stack state without contradicting annotations.

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?

Four short sentences, all carrying distinct value: action, return behavior, usage, and an exclusion with alternative. Front-loaded with the core purpose and no filler or redundancy.

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 parameterless tool with no output schema, the description covers all necessary aspects: what it does, what it returns, when to use it, and when not to use it. An agent can invoke it correctly without needing any additional information.

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?

There are zero parameters, so schema coverage is trivially 100%. Baseline for 0-param tools is 4, and the description appropriately focuses on return behavior rather than parameter details. Nothing further is needed.

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 action and resource: 'Undo the last edit in the editor.' It also includes a clear when-not-to-use with a named alternative (load_scene), which differentiates it from at least one sibling. It does not explicitly contrast with redo, but the core operation is unambiguous from the name and phrasing.

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?

Explicit when-to-use is given: 'Use this to roll back a change you just made.' An explicit when-not-to-use is also provided: 'to switch scenes (use load_scene).' This fully satisfies the highest bar for usage guidance, including an alternative.

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