fl_undo

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

Annotations already declare readOnlyHint=false, destructiveHint=true, and idempotentHint=false. The description adds useful context by noting the movement is to an absolute undo-history position and that verification occurs, but it does not disclose failure behavior or redo implications beyond what annotations provide.

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 waste. It states the action and the verification postcondition clearly, and every word contributes to understanding the tool's core behavior.

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?

Combined with the detailed parameter descriptions, annotations, and the presence of an output schema, the description is largely complete enough for correct invocation, including calling with no required parameters. It could be more explicit about prerequisites or alternatives, but the structured fields substantially reduce the burden on the description.

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 description coverage is 100%, and both optional parameters already have thorough descriptions, including the expected_before history guard and the session_fingerprint concurrency guard. The description itself adds no parameter info, but the schema carries the burden, so baseline 3 is appropriate.

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 what the tool does: it moves to the previous absolute undo-history position and verifies the result. The verb and resource are specific, and the word 'previous distinguishes it from the sibling fl_redo tool without ambiguity.

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?

Usage is implied rather than explicit: the description conveys that you use this tool when you want to step backward in project history, but it does not name alternatives such as fl_redo or fl_get_project_history or state when not to use them. This is adequate but not strongly directive.

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