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

Annotations already cover safety (readOnlyHint=false, destructiveHint=false, idempotentHint=true, openWorldHint=true), and the description adds a genuinely useful behavioral fact: it charges the shared wallet the monthly fee. However, the remaining sentence ('A direct Widely connection runs it immediately') is opaque and the description says nothing about failure modes, prerequisites, or what state changes on the number.

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 short sentences with no padding, and the core capability leads. But the last sentence is cryptic rather than informative, so brevity comes partly from under-explanation rather than tight writing.

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 billed, state-changing tool with zero parameter documentation and no output schema, the description omits what the call returns, how monitor_ids affects behavior, and what happens when activation fails or is already active. Only the billing fact is covered; the rest is left to guesswork.

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 0%, so three parameters (did_id, ivr_config_id, monitor_ids) carry no documented meaning anywhere. The description gestures at a 'number this account owns' but never maps it to did_id, never explains ivr_config_id or monitor_ids, and gives no format or selection guidance to compensate for the coverage gap.

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?

The description states the effect concretely: answering WhatsApp for a number the account owns via that number's AI receptionist, which an agent can read as 'turn on the WhatsApp AI receptionist'. It never distinguishes itself from the sibling update_whatsapp_ai (or add_number_channels), so the agent is left to infer whether this creates, enables, or modifies.

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?

There is no explicit when-to-use, when-not-to-use, or alternative named among the many siblings. The only implicit scoping is 'a number this account owns', which hints at a prerequisite but is not framed as guidance, and nothing tells the agent when to prefer update_whatsapp_ai instead.

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