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

Annotations declare a non-read-only, open-world, non-destructive operation, and the description adds value beyond that: the response contains an API key that must be persisted in the connector configuration, and the code must come from the user rather than being fabricated. It doesn't cover failure modes such as an expired or already-used code, 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?

Three short sentences, each doing work: what the tool does, the procedure with the user, and what to do with the returned key. The critical constraint (never invent the code) and the post-call action are both front-loaded and unambiguous.

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?

Since an output schema exists, return values needn't be enumerated, and the description still flags the API key as the important output and what to do with it. The only gaps are error/retry behavior and the unmentioned optional `client` parameter, which are minor for this flow.

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%, so the baseline is 3. The description's guidance on the email ('same email used in signup') largely restates the schema, and the optional `client` parameter is not mentioned at all, so it adds little semantic meaning beyond the structured fields.

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 outcome: completing the CortexPlus connection using the 6-digit signup code. It clearly distinguishes this tool from the sibling `signup` by framing itself as the post-signup completion step, so an agent can route between them without opening 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?

Explicit when-to-use (after the user receives the email code), an operational precondition (call with the same email used in signup), and a negative instruction (never guess or invent the code). It also tells the agent to ask the user for the code first, leaving nothing to inference.

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