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

The description adds meaningful behavioral context beyond the annotations: it is free and unmetered, a human reviews it before publication, and re-sending the same promo_ref updates the pending promotion rather than creating a duplicate. These are real behavioral traits not expressed by the annotations, and the conditional idempotency via promo_ref does not directly contradict idempotentHint=false.

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?

The description is compact and front-loaded: the first sentence states the core operation, the second adds cost/cost context, and the third explains the review and idempotent update behavior. Every sentence 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?

For a mutation-oriented tool with no output schema, the description covers the key prerequisites, review latency, and update semantics. Remaining gaps are mostly about return values and less central parameters, but the invocation path is clear enough for an agent to use it correctly.

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 50%, and the description helps clarify the meaning of kind, the business linkage, and the promo_ref update behavior. However, it adds nothing about terms, detail, discount_pct, starts_at, or ends_at, so it does not fully compensate for the parameters left undocumented in the schema.

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?

The description clearly states a specific action: attach a promotion, special, event, or ad to a previously submitted business. This distinguishes it from the sibling num_submit_business, which must be called first to create the business.

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?

The description gives a clear precondition: the business must already have been submitted by the same account. It does not name alternative tools or explicitly say when not to use it, but the context of attaching to an existing submission is enough for an agent to route correctly.

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