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

Annotations already flag destructiveHint=true and idempotentHint=true, but the description adds consequences the annotations cannot convey: calls stop routing only once deprovisioning completes, messaging is untouched because it belongs to the connected account, and reversal costs a full re-provisioning cycle. These are the exact post-conditions an agent needs before invoking an irreversible-feeling operation.

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 tersely packed sentences with the destructive warning front-loaded and zero filler. The messaging-unaffected clarification is slightly parenthetical but earns its place by preventing a common misread.

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 annotations already covering the safety profile, the description supplies the remaining essentials: blast radius (calling only), timing (routing stops on completion), and reversibility cost. Nothing needed to call this correctly 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 description coverage is 100%, including the critical 'tenant number UUID (from list_numbers) — NOT the trunk id' clarification, so the schema already carries parameter meaning. The description reinforces that the target is a number rather than a trunk but adds no syntax or sourcing detail beyond what the schema states, making the baseline 3 appropriate.

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 ('deprovision a number's WhatsApp calling trunk') and immediately disambiguates scope by noting that WhatsApp MESSAGING is unaffected. That distinction is exactly what separates it from the broader number/messaging siblings like release_number or delete_whatsapp_media, and from enable_whatsapp_calling.

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 a clear operational precondition ('Always confirm with the user first') and implies when-not via the warning that re-enabling starts a fresh provisioning cycle. It does not explicitly name a sibling alternative or state the conditions under which disabling is the right call versus, say, rotate_whatsapp_trunk, so it falls short of a full when/when-not/alternatives treatment.

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