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

Annotations already declare destructiveHint=true and idempotentHint=true, but the description adds what those hints cannot: in-flight calls are allowed to finish rather than being dropped, and the pause is not terminal. Calling it destructive while also reversible is a nuance rather than a contradiction. It does not mention permissions or what a success response confirms.

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 the operation first, the identifier options inline, and the two behavioral caveats trailing. Nothing is padded or restated from the title.

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 two-parameter mutation with no output schema and a rich annotation set, the essentials — what halts, what finishes, and that it is resumable — are all covered. Missing only secondary detail such as whether the response reports the campaign's new state or how to recover the identifier.

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 0% and both parameters are nullable with zero required, so the description must carry meaning — and it does clarify that one of `voip_campaign_id` or `voip_campaign_uuid` identifies the campaign, implying at least one is needed. It does not say whether both may be supplied, which takes precedence, or where the values come from (create/list_voip_campaigns).

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 — 'Stops dialling a running campaign' — scoped to the VOIP campaign identified by id or uuid. Along with the '[write]' prefix and the note that it can be started again later, an agent can separate this from start_voip_campaign and from pause_ads_campaign without opening either schema.

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?

Implies the precondition ('a running campaign') and the reversibility ('can be started again later'), which nudges the agent toward start_voip_campaign when it wants the opposite action. It stops short of naming the alternative tool or stating when pausing is the wrong choice, so it sits just below full guidance.

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