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

Annotations already flag destructiveHint=true and readOnlyHint=false, but the description adds real value by enumerating the three refusal conditions (contents changed afterward, move target occupied, unknown crash outcome) and the scope limits. It does not state idempotency or return behavior, so it is strong rather than exhaustive.

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?

Three short sentences, verb and resource front-loaded, then the required-ID instruction, then failure modes and scope limits. No filler and no repetition of structured data.

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 destructive mutation with no output schema, the description covers the action, the required identifiers, refusal conditions, and scope boundaries. The only gap is the provenance of changeId, which an agent needs to actually invoke it.

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 67%: deviceId and workSessionId carry schema descriptions, while the required changeId has none. The description reinforces that workSessionId must be the original session, but never explains where changeId comes from (e.g., list_file_changes), leaving the most important parameter under-documented. Baseline 3 fits.

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 (undo) and a precisely scoped resource (one retained file edit/write, move or copy), and keys the operation to changeId. An agent can distinguish it from siblings like list_file_changes or remove_path without opening a schema.

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?

Gives clear operating context (pass the original workSessionId, identify the change by changeId) and explicit exclusions (does not undo terminal commands or permanent deletions). It stops short of naming an alternative for the excluded cases, so a 5 is not warranted.

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