finish_change_number

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

With no annotations provided, the description carries the full responsibility for behavioral disclosure. It explains that on success the account is permanently migrated and all linked devices are updated. It could mention irreversibility more explicitly, but overall it is transparent about the outcome.

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 three sentences with no fluff. The first sentence states the core action, and subsequent sentences add prerequisite and parameter details. Every sentence earns its place.

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 the tool's simplicity, no output schema, and the good annotations from schema and description, the description covers the necessary context: prerequisites, parameter details, and effects. No gaps remain.

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 provides 100% coverage with descriptions, but the tool description adds valuable context: it specifies that 'number' is the new E.164 format, 'verification_code' is the 6-digit code received, and 'pin' is required only if a Registration Lock PIN is set. This goes beyond the schema's basic descriptions.

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 explicitly states that it completes the second step of a phone number change by submitting the verification code, clearly identifying the verb ('complete'), resource ('phone number change'), and scope ('second step'). It also distinguishes itself from its sibling tool start_change_number.

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: must be called after start_change_number, which initiates the change and triggers the code. It also warns not to call without first calling start_change_number, and explains the conditional use of the pin parameter.

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