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

Annotations mark readOnlyHint=false and destructiveHint=false, which alone leaves an agent guessing whether a call mutates the ad account. The description resolves this by declaring no account change, naming the return value (proposal_id plus preview), and prescribing the follow-up apply_change step.

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 non-mutation guarantee and the required confirmation flow; nothing is repeated or wasted.

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 the brief return-value mention suffices. The one minor gap is that the schema less-than-obvious path for unknown/missing fields returning a schema is only documented in the nested field description, not reinforced here.

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%, including platform-specific mapping notes for ad_set_id, account_id, and campaign_id, so the description adds no parameter meaning. 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 new ad') and immediately contrasts it with the real mutation path ('Does NOT change the account'), which cleanly separates it from apply_change and the propose_update_* siblings.

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 explicit sequencing guidance: show the preview, then call apply_change(proposal_id) only after user confirmation. It doesn't say when to pick this over propose_change or propose_create_campaign, but the staging workflow it describes is unambiguous.

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