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

Beyond annotations, the description reveals the ~20s timeout, the four possible statuses, how to handle successful completion (store sessionToken, refreshToken, grantId), the 7-day refresh window, the 1-hour session expiry, and the server-side token binding. The warning that a device claim is not a billing upgrade adds extra caution. This is exemplary behavioral disclosure.

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?

Every sentence earns its place: core polling behavior, timeout, statuses, token handling, expiry, follow-up action, and a clarifying warning. The description is front-loaded with the primary purpose and contains 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?

There is no output schema, but the description provides all critical runtime information: statuses, token field names, expiry durations, the follow-up tool (refresh_session), and parameter nuances. An agent has enough to call the tool correctly and handle its result appropriately.

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%, giving a baseline of 3. The description adds meaning by identifying the source of the code parameter (get_pairing_code / whoami) and explaining that tenantId improves lookup after phone approval. This extra context goes beyond the schema and justifies a 4.

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 ('Poll'), a clear resource ('pairing completion'), and names the Device-Grant style, making the core purpose obvious. However, it does not explicitly differentiate itself from the sibling tools poll_approval and poll_decision, which also sound like polling workflows, so it falls just short of a 5.

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 implies the main use case: after obtaining a code via get_pairing_code, poll until the phone approves, with a ~20s wait. It also gives explicit follow-up guidance to call refresh_session when sessionToken expires. However, it does not explain when to prefer poll_pairing over poll_approval or poll_decision, so alternative-routing guidance is missing.

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