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

Adds real context beyond the annotations: it does not mutate the account, it returns a proposal_id plus a preview, and it is a human-in-the-loop step. It does not mention that repeat calls are non-idempotent (annotations flag idempotentHint=false) and produce multiple proposals, which would be a useful caveat.

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, front-loaded with the action and its non-mutating nature, then the follow-up workflow. No filler and nothing repeated from the schema.

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 and full parameter documentation carry most of the load, and the description covers the non-mutating behavior and confirmation flow. The only gap is the duplicate-proposal risk from non-idempotent calls, which matters for a staging tool.

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%, so platform, entity_id, account_id, and fields are already documented, including platform enum values and the fields semantics. The description adds nothing further about parameters, so the 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 and resource ('Stage a change to an existing campaign') and draws the key line against apply_change by saying it does not modify the account. It doesn't address how it differs from the similarly named propose_change sibling, which an agent working from names alone might confuse it with.

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 an explicit workflow: stage here, show the preview, and call apply_change(proposal_id) only after user confirmation. That names the alternative tool and the condition that gates the switch, leaving nothing to inference.

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