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

Annotations already declare destructiveHint=true, idempotentHint=true and readOnlyHint=false, so the safety profile is largely covered. The description adds genuinely new context — the UI-only availability constraint and the fact that approval is bound to a specific snapshot and does not trigger scheduling/publishing — but it leaves the destructiveHint unexplained (what approval irreversibly commits) and says nothing about retry behavior despite the idempotencyKey parameter.

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, front-loaded with the action and its scope, followed by the two most decision-relevant constraints (no scheduling/publishing, UI-only). No filler and nothing repeated from the schema or annotations.

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?

It correctly clarifies the mutation's boundaries and availability, and an output schema exists so return values need no explanation. However, with 0% parameter descriptions and a destructive, idempotent mutation, the definition leaves an agent without enough information about the identifiers it must supply or the irreversible nature of the commit.

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 0% across four required parameters, so the description carries the full burden. It conveys the meaning of 'snapshot' via 'the exact campaign snapshot reviewed in the card', but brandId, campaignId and especially idempotencyKey (8-128 chars, presumably replay protection) are never explained, leaving most of the parameter set opaque.

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?

Specific verb+resource ('Approve the exact campaign snapshot') with a stated scope ('including content, settings, assets, facts and times') that pins down exactly what approval binds. It also carves itself off from the adjacent siblings schedule_campaign and prepare_campaign by declaring 'Does not schedule or publish'.

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 context (approval is tied to the snapshot reviewed in the card) and an explicit negative boundary that routes the agent away from schedule/publish. It stops short of saying when to choose this over prepare_campaign or what must precede it, so it is clear context rather than full when/when-not guidance.

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