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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so safety and repeatability are covered. The description adds genuine context beyond them by enumerating the returned fields and disclosing the 'not-found' outcome for a missing instance.

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?

Two sentences, zero filler, and the usage trigger is front-loaded ahead of the return-value list and the exclusion. Every clause carries information an agent needs.

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 a rich annotation set and an output schema present, the description needn't restate return values, and it correctly focuses on when to call it plus the not-found case. The only remaining gap is the unresolved overlap with get_instance_status.

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% and the single instanceId parameter is fully documented in the schema (24 lowercase hex characters, with a regex pattern). The description adds no syntax or format information beyond it, so the baseline of 3 applies.

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+resource: 'one connected WhatsApp number' with the fields it exposes (phone number, account name, connection health). It implicitly separates itself from list_instances by scoping to a single instance. However, it never addresses the near-duplicate sibling get_instance_status, which appears to overlap with the 'status and health' it claims to return.

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?

'Use this when someone asks about one connected WhatsApp number' gives a clear trigger condition, and 'Not for message history, which this connector does not read' is an explicit exclusion. What's missing is disambiguation against get_instance_status, the one sibling most likely to be confused with it.

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