Update campaign

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

Annotations already declare this is a non-read-only, non-idempotent, non-destructive mutation, and the description adds a materially useful behavior the annotations do not: the state gate limiting edits to draft/scheduled/paused campaigns. It stops short of saying what error surfaces or whether changing list_ids drops subscribers, but the state restriction is the key operational fact.

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, each carrying distinct information: what it does, how partial updates behave, and the state precondition. No filler and the important constraint is not buried.

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 10-parameter mutation with no output schema and 0% schema coverage, the description covers the two biggest failure modes (partial updates, campaign state) but leaves every parameter's meaning and validation undocumented. It is adequate to attempt the call safely but not to construct fields correctly without reading the raw schema.

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 0% across 10 parameters, so the schema names fields but explains none of them. The description only adds the partial-update rule ('only the fields you pass change') and says nothing about id, list_ids, send_at null semantics, content_type enum values, or field interactions — the compensating value is thin relative to 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 ('Update a campaign') with no ambiguity about what entity is affected. It does implicitly distinguish itself from campaign_set_status by describing field-level edits, but never names that sibling, so the differentiation is left to inference.

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 ('only allows edits while the campaign is a draft, scheduled, or paused'), which tells the agent when the call will fail. However it never states when to use this versus campaign_set_status or campaign_delete, nor does it say what to do if the campaign is in another state.

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