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

Annotations only say readOnlyHint=false/destructiveHint=false, so the description carries the real burden and does it well: it discloses the returned artifacts (verification_uri_complete, user_code), that a human must approve and pick an account, and that signup is possible. It omits how long the device_code stays valid or what happens on denial/expiry, which keeps it short of a 5.

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?

Roughly 70 words, front-loaded with the precondition, then the return values, then the next call. No filler sentences; the slight run-on is dense rather than wasteful.

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?

No output schema exists, so the description must describe returns and follow-up — it names verification_uri_complete, user_code, device_code, interval and api_key, plus the human hand-off step. Nothing an agent needs to complete this half of the flow is 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 coverage is 100% and there is only one optional parameter (client_name), so the schema already documents it fully. The description never mentions the parameter or that the agent's name is what the approver sees, adding no meaning beyond the schema — baseline 3.

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?

States a specific action (start the sign-in/device-authorization flow) with its precondition, and explicitly names the sibling that continues the flow (assistable_connect_finish). An agent can distinguish it from every other sibling without opening a schema.

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?

"Only when you have no Assistable API key" gives an explicit when-to-use gate, and the follow-up sentence prescribes the next step: call assistable_connect_finish with device_code every interval seconds until api_key is returned. Alternatives and sequencing are both spelled out.

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