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

Annotations cover safety (readOnlyHint=false, destructiveHint=false, openWorldHint=true), and the description adds real value beyond them: it does not spend money, does not reserve funds, and returns a creative plus quote for review. It does not address idempotency despite idempotentHint=false and a requestKey parameter, which is a minor gap.

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?

Front-loads the core action and the non-spend constraint in the first two sentences. Mostly tight, though the garbled phrase 'oriiion shared advertiser identity' adds noise and slightly obscures the approval condition.

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 complex 11-required-param mutation with no output schema, the description usefully hints at the return value (creative and current quote) but leaves the parameter semantics largely unexplained. Adequate for routing, incomplete for 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 description coverage is 0% across 11 required parameters, so the description must carry the burden. It gestures at budget, duration, and advertiser identity conceptually but never explains bidCents, goal, countries, requestKey, or the creative fields, leaving most inputs undocumented in both schema and prose.

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 ('Save a ChatGPT ad DRAFT') and immediately bounds the scope with 'Does not launch, reserve funds or spend money.' It distinguishes itself from the sibling start_chatgpt_ad and edit_chatgpt_ad by making the draft-only nature explicit.

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?

Explicitly routes the agent: 'Use start_chatgpt_ad only after the user approves the exact budget, service fee, duration and ... shared advertiser identity,' and adds the prerequisite 'No campaign-builder page is needed.' This is a clear when-to-use / when-to-escalate statement with the alternative named.

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