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

Goes well beyond the annotations (readOnly=false, destructive=false, idempotent=true) by disclosing that creation only produces a draft, that delivery is a dry run until the operator enables sending, and that an approval/scope gate applies. It also explains stop-rule semantics (reply, bounce, unsubscribe, deal stage change) that materially change runtime behavior.

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?

Front-loaded with the core definition and the lifecycle guidance, with no filler sentences. The opening sentence is long and densely packed with feature nouns, but every clause carries information an agent needs.

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 15-parameter nested-object tool with no output schema, the description covers the lifecycle, the dry-run safety model, scope requirements and inline step/enroll semantics. It does not describe what is returned (presumably a campaign id) or the default identity/strategy approval flow in detail, but nothing critical to correct invocation is missing.

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 93%, so the baseline is 3, and the description adds real meaning on top: 'pass steps inline', 'enroll selects contacts in the same call using the same selectors as enroll_contacts', and the stop_on values are explained as things that halt a contact's sequence rather than just enumerated.

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 and then defines what a campaign actually is (an ordered sequence of email, wait and task steps run per contact, with stop rules, send window, caps and A/B variants). That definition distinguishes it from siblings like update_campaign or launch_campaign, which operate on an already-existing campaign.

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 workflow: the campaign starts as a draft, then call simulate_campaign, then launch_campaign — that is genuine routing guidance. It also states the required manage_campaigns scope. It stops short of naming when to prefer update_campaign over creating a new one, so not quite a 5.

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