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

Annotations already establish read-only and closed-world behavior, and the description adds substantial operational context beyond that: empty-result polling semantics, retry timing, auto-refund within 10 minutes, no charge for ordering again, and charging only for codes that arrive. This is unusually complete for a polling tool.

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?

The description is front-loaded with the core polling behavior and result semantics, then moves directly into failure handling. Despite covering several operational rules, every sentence is actionable and no sentence is redundant.

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?

There is no output schema, but the description fully explains the possible return outcomes: the code when it arrives or an empty result requiring another poll. It also supplies the failure workflow, refund behavior, and billing behavior needed to call and recover from this tool correctly.

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 coverage is 100%, and the single orderId parameter is already documented as coming from create_otp_order. The description does not add format, source, or validation details beyond the schema, so baseline 3 is appropriate.

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 specific action and resource: check for the SMS/OTP code on an order. It also explains the result shape, returning the code once it arrives or an empty result otherwise, which makes the tool's purpose unambiguous and distinguishable from setup siblings like create_otp_order.

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 explicit polling guidance ('poll again after a few seconds') and a concrete escalation path after one to two minutes: order a fresh number with create_otp_order, prefer the us1 Non-VoIP pool, leave the original to auto-refund, and never cancel just to retry. This directly covers when to use the tool, what to do on failure, and which alternatives not to use.

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