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

Annotations already declare readOnly, idempotent and non-destructive, so the safety profile is covered. The description adds genuinely useful context beyond that: the status lifecycle, the fields returned, and an admin-only access restriction.

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 tight sentences, zero filler, with the core capability front-loaded and the admin restriction placed last. Every clause carries information.

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?

With no output schema present, the description usefully discloses the returned fields (statuses, recipient counts, message text, accountId). It is nearly complete; only secondary details like ordering, pagination or result limits are unmentioned.

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?

The tool takes zero parameters, so there is no parameter syntax to explain and the baseline is 4. The description correctly does not waste space on nonexistent inputs.

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?

Specific verb ('List') plus a precise resource ('DM broadcast campaigns'), and it enumerates the status values and return fields. It is cleanly distinguishable from siblings like list_broadcast_contacts and create_broadcast, which handle different resources or operations.

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?

Usage is implied by the enumeration of statuses and the note that it returns accountId values 'to use when creating one', which softly points at create_broadcast. However, it never explicitly states when to call this versus list_broadcast_contacts or that it should be called before creating/sending a broadcast.

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