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

Annotations already declare this is a non-read-only, non-destructive, non-idempotent write, so safety is covered. The description adds real behavioral context beyond that: creation is scoped to the authenticated agency, omitting refresh_cadence silently defaults tracking to on-request, and automatic tracking will not engage without a future ends_at. It does not address auth granularity or failure modes.

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, zero filler, with the ownership scope and the two tracking rules front-loaded in order of importance. Nothing is repeated from the title or schema verbatim.

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 7 parameters, full schema coverage, annotations, and an output schema, the description only needs to carry the non-obvious behavioral rules, and it does. The main omission is any statement of what the call returns on success, though the output schema largely covers that.

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%, so the baseline is 3, but the description adds a cross-parameter rule the schema only states partially: the refresh_cadence-omitted default and the ends_at future requirement for automatic tracking. The default itself is already in the schema, so the gain is modest rather than large.

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 ('Create a campaign') plus an ownership scope ('owned by the authenticated agency'), which is enough to distinguish it from campaign_get and campaign_update by verb alone. It never explicitly names or contrasts with those siblings, so it stops short of a 5.

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 conditional guidance about tracking modes but frames it as parameter behavior rather than when to pick this tool over alternatives like campaign_update or campaign_list. Usage is implied by the create verb, not stated with exclusions or prerequisites.

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