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

Goes well beyond annotations by disclosing the pending_payment state transition, the 20-minute hold window, and the returned callpaymin.io payment link, plus the explicit safety claim that no card is charged or wallet debited. It does not explain how the idempotencyKey should be used despite idempotentHint=false, which matters for retry safety on a hold-creating call.

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, front-loaded with the default (quote-only) behavior and then the conditional confirm path. Every clause carries decision-relevant 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?

For a mutating, open-world tool with no output schema, the description supplies the return shape (price vs. payment link) and the lifecycle after the call. Remaining gaps are retry/idempotency guidance and conflict handling, which are real but secondary.

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 the description carries the burden, and it only explains confirm and acknowledgedCostUsd (including that the latter must equal estimatedCostUsd). The other six parameters – expertId, start, durationMinutes, callType, notes, idempotencyKey – get no semantic treatment at all.

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 a concrete verb and resource ('Quotes a scheduled call', optionally holds the slot) and makes the two-mode behavior explicit, which is more than the title alone conveys. It does not distinguish itself from the nearby sibling 'estimate_call_cost', which sounds like an overlapping quote operation, so an agent must still infer which one to call.

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?

It gives an explicit when-to-use split: omit confirm to get a price only, pass confirm=true plus a matching acknowledgedCostUsd to actually hold the slot. It does not state what to do if the price has changed since estimating, nor point to 'estimate_call_cost' as the read-only alternative.

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