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

Annotations only declare the generic write profile (readOnlyHint=false, destructiveHint=false, idempotentHint=false). The description adds genuinely non-obvious context: the scope is limited to the caller's own last change, and other people's edits are preserved. It stops short of covering failure behavior when the redo stack is empty, which keeps it from a 5.

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?

Two short sentences with the action front-loaded and the side-effect guarantee second. No wasted words, though 'Makes again' is less crisp than 'Reapplies' and slightly slows parsing.

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 simple one-parameter mutation with annotations and no output schema, the description covers the essential scope. It omits the paired undo_change relationship and the no-op/error case, which an agent would need to call this confidently in a redo workflow.

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?

Only one parameter, and schema description coverage is 100% – the schema already explains project_id and even the display rule. The description adds nothing further about the parameter, so baseline 3 applies.

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?

States a specific verb-like action ('Makes again') on a specific resource ('your own last change to a plan'), which implicitly contrasts with the sibling undo_change. However, it never names undo_change or explains that this is the inverse operation, so the differentiation is left to inference and the phrasing is slightly awkward.

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 trigger condition is implied by 'Makes again your own last change' – an agent can infer this is used to reapply a reverted edit. But there is no explicit when-to-use, no mention of the undo_change alternative, and no guidance on what happens when there is no change to redo.

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