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

Annotations already cover readOnly/idempotent/non-destructive, so 'Read-only; changes nothing' earns no credit. Beyond that, the description adds real behavioral depth: readiness requires the same proof the channel's own tool needs (approved text registration for texts to callers, verified number for WhatsApp), and email readiness is split between managedEmail campaign sender readiness and a connected mailbox. This is meaningful context an agent cannot get from the annotations alone.

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?

Front-loaded with the verb, resource, and state vocabulary in the first sentence, followed by row semantics and caveats. Some sentences (the managedEmail campaign sender nuance) are long and dense, but each carries non-redundant information, so little 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?

An output schema exists, so return structure needn't be re-explained; the description instead supplies the interpretive layer (state definitions, proof requirements, next-step routing) that makes the output actionable. The only gap is that it doesn't position itself against the per-channel status siblings an agent might otherwise pick.

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?

One parameter (business_id) with 0% schema description coverage, and the description never mentions it or its format. The parameter is largely self-evident from its name, so this is not a severe gap, but the description adds nothing over the schema here.

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 (List) and resource (every customer channel a business can have) plus the enumerated states it returns (ready, needs_setup, blocked, not_available). This clearly marks it as the aggregate channel-readiness view, distinguishable from narrower siblings like get_whatsapp_status, get_phone_system_status, and get_activation_status.

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?

Provides strong interpretation context: each row says whether a message can go out and whether customers can reach the business, and names the next-step tool to use. It does not explicitly state when to prefer this tool over the per-channel status siblings, so it stops short of the when/when-not/alternatives bar.

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