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

Annotations only declare the operation is a non-destructive, non-idempotent, non-open-world write. The description goes well beyond that by disclosing the human-in-the-loop approval step, the returned artifacts (link, code, deviceCode), and the security constraint about pasting keys. It stops short of mentioning code expiry or what happens if approval never occurs, so a 4 rather than 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?

Three short sentences, front-loaded with the action and its key constraint. Every clause carries information an agent needs: the no-key rule, the returned values, and the handoff to finish_login.

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, so the description compensates by naming the return values and how they are consumed downstream. For a zero-required-parameter auth-initiation tool, nothing an agent needs in order to call it and follow up correctly 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 description coverage is 100% and the schema itself explains both name (how the human recognises the agent) and client. The description adds no parameter-level meaning beyond that, so the baseline 3 applies.

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 verb and resource (connect the agent to the human's Kivel workspace) and immediately scopes the alternative (no API key needed). It also names the sibling it hands off to (finish_login), so an agent can place it in the auth flow without inspecting schemas.

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?

Implies this is the entry point of a two-step flow and explicitly routes the deviceCode to finish_login. It also gives a concrete prohibition (never ask the human to paste an API key), which is real usage guidance. Missing an explicit statement of when not to call it, e.g. if already authenticated, which keeps it from a 5.

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