provision_number

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

With no annotations, the description bears the full transparency burden. It discloses that the number is temporary, leased for a session, and will be released after ttl_seconds. It mentions the webhook option but does not detail expiration behavior or side effects. Overall, it provides good behavioral context.

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 concise (three sentences) and front-loaded: first sentence states purpose, second sentence details output, third sentence gives action steps. Every sentence adds value without redundancy.

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?

Given that an output schema exists, the description does not need to detail return values. It covers key outputs (number, session_id) and next steps. It lacks preconditions or error cases but is complete for a provisioning tool. A minor gap is not mentioning what happens if agent_id is already in use.

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?

The input schema already has descriptions for all parameters (agent_id, country, ttl_seconds, webhook_url). The description adds context about the lease duration and the next steps but does not significantly enhance parameter meaning beyond the schema. Baseline 3 is appropriate given high schema coverage.

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 tool's purpose: leasing a temporary phone number for receiving SMS OTP codes. It specifies the output format (e164 number and session_id) and distinguishes it from sibling tools by mentioning the next step 'wait_for_otp'. No ambiguity.

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 provides explicit guidance on when to use this tool and what steps follow (trigger SMS, then call wait_for_otp). It also notes the number is reserved for the session duration. While it doesn't explicitly state when not to use it or alternatives, the context from sibling tools is sufficient.

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