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

Annotations already cover read-only, idempotent, closed-world, non-destructive, so the description is free to spend its words on behavior that structured fields cannot express. It does exactly that: it discloses the attribution model (last human click, seven-day window, per-currency separation), warns that results are attribution and not causal revenue or inbox proof, and clarifies no provider calls or inference credits are consumed. These are meaningful interpretive constraints an agent could not derive from the annotations.

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 core outcome/attribution claim is front-loaded in the first sentence, and the caveats follow in declining priority. The final sentence is elliptical to the point of abstraction ('No event-date-range claim, provider calls, sending or inference credits'), which reads as compressed internal shorthand rather than clean prose.

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?

With an output schema available, the description needn't describe return values, and the annotations carry the safety profile. What remains needing explanation for a one-parameter read tool — the attribution model, currency handling, and the epistemic limits of the numbers — is fully covered.

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% and the single campaign_id parameter is documented in-schema as an exact campaign or ticket identifier within the authenticated organization. The description's 'exact-organization' wording reinforces tenant scoping but adds no format, length, or lookup semantics beyond the schema, so this lands at the baseline.

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 names a specific verb and resource ('Read one exact-organization campaign's lifetime recorded delivery/open/click outcomes') and scopes it to clicker classification and attributed orders. It implicitly separates itself from campaign-config or send-run siblings by stressing lifetime aggregates rather than events, but it never names a sibling explicitly, so an agent must infer the boundary rather than be routed.

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?

Usage is implied: call this to retrieve outcome/attribution data for a single campaign. The closing sentence lists what the tool does NOT cover (event date ranges, provider calls, sending), which functions as a soft exclusion, but there is no positive 'use this instead of X when Y' guidance and no prerequisites stated.

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