Check SMS Code

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering the safety profile. The description adds meaningful behavioral context beyond annotations by disclosing the return contents (status, phone_number, messages[] array, extracted code) and the recommended polling cadence. The description does not contradict any annotation.

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 carry purpose, return shape, polling guidance, and sibling routing with zero filler. The core statement ('Check if an SMS verification code has been received for an order') is front-loaded, and every subsequent clause adds value.

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 one-parameter, read-only, idempotent polling tool, the description covers everything needed to invoke it correctly: what it does, what it returns, when to poll, and when to choose the alternative. Although there is no output schema, the description compensates by listing the returned fields, making the tool self-contained.

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%, so the single parameter order_id is already fully documented as 'Order ID returned from create_order'. The description adds no extra parameter detail beyond the schema, which warrants the baseline 3 for high coverage. No compensation needed.

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 verb ('Check') and resource ('SMS verification code for an order'), making the tool's function clear. It also differentiates from the sibling tool wait_for_sms by explicitly naming it as the blocking alternative. An agent can immediately identify this as the non-blocking polling variant.

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?

The description gives explicit when-to-use guidance: 'Poll this every 5-10 seconds after buying a number'. It also names the alternative ('wait_for_sms') and the condition that selects it ('to block until delivery'). This is model usage guidance for a polling tool.

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