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

Annotations declare readOnlyHint=true, but canceling a campaign changes its state by stopping dialing, which is a mutation. The description ('Cancel a campaign') therefore contradicts the readOnlyHint annotation, and no additional behavioral context (reversibility, effect on history) is provided to resolve the conflict.

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 single front-loaded sentence with zero filler. The core action and its consequence are stated immediately, and nothing is wasted.

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 state-changing tool with no output schema and misleading annotations, the description omits whether cancellation is reversible, whether it deletes campaign data or call history, and how it relates to pause. It also provides nothing to correct the readOnlyHint contradiction an agent would otherwise trust.

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 50%: in_workspace is documented in the schema, while campaign_id is self-evident as the required identifier. The description adds no parameter-level detail (e.g., format, scope, or side effects of in_workspace), so it does nothing beyond the partially-covering schema.

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 (Cancel) and resource (campaign) and adds the operational consequence that no further numbers are dialed. It does not, however, distinguish itself from the sibling campaigns_pause, which is the distinction an agent most needs when deciding between stopping and pausing a 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?

There is no explicit when-to-use guidance or mention of alternatives such as campaigns_pause or campaigns_resume. The title of the sibling set implies a pause/cancel contrast exists, but the description never tells the agent which condition selects cancel over pause.

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