Swap Phone Number

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

Discloses key behavioral traits beyond annotations: free swap, cooldown period, error scenario (cooldown_active). Annotations indicate non-read-only but description adds richness about conditions and outcomes.

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?

Very concise: two sentences with main purpose and a separate note for cooldown. Every sentence adds value, no fluff. Information is front-loaded.

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 simple tool with one parameter and no output schema, the description covers purpose, usage scenario, preconditions, cooldown, and error handling. Nothing missing.

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 covers the single parameter with a description, but the tool description adds critical context: the order must be in waiting/created status with no SMS received. This goes beyond what schema alone provides.

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 clearly states the action ('Swap a phone number on an existing order') and the resource ('Gets a new number for the same service and country without additional charge'). It effectively distinguishes from sibling tools like virtualsms_create_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?

Explicitly states when to use ('Use when the current number isn't receiving SMS') and includes a cooldown condition with specific timing (120 seconds) and error handling advice ('Check swap_available_at on the order before calling'). Provides clear guidance on when not to use.

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