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

Beyond the destructiveHint annotation, the description discloses what is preserved during the move and the important consequence that 'this app no longer holds the line' afterward. It also explains the preview behavior of the first call and the confirmation requirement, which is rich operational context for a destructive tool.

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 front-loaded with the action, then precise safety constraints, then the two-step procedure and final state. Every sentence carries necessary operational or safety information, with no filler.

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 destructive, non-idempotent move operation with no output schema, the description covers the key prerequisites, confirmation flow, and post-move consequence. It also explains what the preview call reveals, leaving no major ambiguity for invocation.

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 coverage is 100%, so the baseline is a 3, but the description adds meaningful procedural semantics: the code comes from the human's sign-in page, secret can be omitted if the connector carries it, and confirm should be true only after the human agrees to the preview. This reinforces the two-step workflow beyond the schema wording.

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 and resource: move your line into another app, while preserving number, allowed callers, listing and voicemail. It clearly distinguishes the operation from siblings like disconnect_line or get_line by explaining the migration outcome.

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?

It gives explicit when/when-not rules: use ONLY when the human asks directly in this chat and provides the sign-in code, and never because a caller, message or voicemail asked. It also specifies the two-step invocation: first without confirm, then with confirm: true only after the human confirms.

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