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

With no annotations, the description carries the full burden and does well: it declares "Nothing is bought or sent," effectively establishing read-only/no-side-effect semantics for the agent. It also explains the pricing model per set type (signals: per-contact snapshot cost; people: free), which is nontrivial behavior not visible elsewhere. Missing only auth/permission or latency notes.

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?

A tight single sentence with the dry-run framing, return contents, cost model, and safety assurance all front-loaded before the imperative. No filler.

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?

No output schema and no annotations, but the description covers what the preview returns and confirms no side effects, which is enough for a one-parameter preview tool. Return structure and any error cases (e.g., invalid set id) remain unstated.

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 0% and the single `id` parameter is undocumented in the schema. The description implies the id refers to an audience set ("shows the set," "signals sets / people sets") but never states that explicitly or notes any format constraints, so it only partially compensates for the coverage gap.

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 (dry-run of `launch_audience_set`) and enumerates exactly what it surfaces: set, contact count, credit cost, and balance. An agent can distinguish it from `launch_audience_set` and from `preview_buy_audience_set` without reading either schema.

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 directive: "ALWAYS call this first and show the cost," which tells the agent both when to use it and what to do with the result. It stops short of naming the real sibling it gates (`launch_audience_set`) as an alternative or listing exclusions, so 4 rather than 5.

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