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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered. The description does add one useful behavioral fact beyond annotations — that results include received codes rather than just numbers — but says nothing about pagination behavior, code lifetime, or what an empty result means.

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 compact sentences with the resource and the key output detail front-loaded; nothing is wasted. The brevity is efficient but borders on under-specification for a three-parameter paginated list.

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?

An output schema exists, so return values need not be described, and the readOnly annotations remove the need for safety prose. However, for a tool with an active/archived filter and cursor pagination, the silent tab and per_page parameters leave a real gap the description should have closed.

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 only 33%: last_id is documented in the schema, but tab and per_page have no descriptions at all. The description does not explain what active versus archived means, what per_page defaults to, or how cursor pagination is meant to be driven, so it fails 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?

"List the current account's one-time numbers with their received codes" gives a specific verb plus resource and scope, and the "one-time" qualifier implicitly separates it from sms_rental_list_numbers. It never names the rental sibling explicitly, so the differentiation relies on the reader noticing the adjective.

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?

No statement of when to call this versus sms_activation_get_code or sms_rental_list_numbers, and no guidance on choosing the tab value for active versus archived numbers. Usage is only inferable from the tool name and verb.

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