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

The description adds a human-approval gate and the immutability property ('exact immutable plan') that annotations cannot express, which is meaningful context for a destructiveHint=true tool. It omits what actually happens on confirm — whether changes execute immediately or a separate apply_* call is still required — and gives no guidance for hash/version mismatch.

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 sentences, zero filler, with the identity constraint front-loaded and the precondition second. Every clause earns its place.

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?

An output schema exists, so return values needn't be explained, and the safety profile is carried by annotations. However, for a destructive commit step in a multi-tool workflow, the description leaves the critical question open: whether confirming itself applies changes or merely locks the plan for a later apply_* call. That ambiguity is material to correct invocation.

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 75%, so most parameters are already documented (planId, planHash, expectedItemCount); planVersion has no description. The phrase 'exact immutable plan' hints that all four params together pin plan identity, but the description adds no meaning about what a version or hash mismatch implies. Baseline 3 is warranted.

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?

Names a specific verb ('Confirms') and a specific resource ('the exact immutable plan the customer reviewed'), which places it clearly in the prepare/confirm/apply lifecycle. It does not explicitly name the sibling it is *not* (get_workflow_plan, cancel_workflow_plan, apply_*), so an agent must infer the distinction from the lifecycle vocabulary.

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?

'Call only after explicit customer approval of old/new values' is a concrete, actionable precondition that tells the agent when to invoke it. It stops short of naming alternatives (e.g. cancel_workflow_plan when approval is withheld, get_workflow_plan to re-review), so the routing is implied rather than explicit.

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