unity_undo_last

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

No annotations are provided, so the description fully bears the burden of transparency. It discloses the linear undo nature, the default refusal to cascade, and the effect of the force parameter. It also clarifies that reads and execute-code are never undo targets, giving the agent a comprehensive understanding of the tool's behavior.

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 sentences with parenthetical clarifications, efficiently conveying all necessary information without waste. It front-loads the main action and then details conditions and exceptions, making it easy for the agent to scan and understand.

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 description is thorough for a simple undo tool: it covers purpose, parameters, behavioral quirks, and references related tools. However, it does not explicitly describe the return value or confirmation message, and no output schema exists. This minor gap prevents a perfect score.

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%, but the description adds meaningful context beyond the schema: the port parameter gets a usage hint ('Always include it when multiple instances run'), force is explained in terms of linear undo, and agentId is linked to unity_undo_history. This extra value elevates it above the baseline of 3.

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 it reverts the most recent undoable MCP action as a whole, distinguishing from individual steps and sibling tools like unity_undo_history and unity_redo. It specifies that execute-code and reads are never targets, making the purpose precise and unambiguous.

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 explicit guidance on when to use this tool (revert most recent action) and how it behaves with linear undo (refuses to cascade unless force:true). It also explains using agentId to target a specific agent's action and references unity_undo_history for agent ids, offering clear usage context.

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