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

Annotations already declare readOnly=false, idempotent=true, and destructive=false, so the safety profile is covered. The description adds useful context beyond that: a prerequisite (owner approval) and a security obligation ('keep returned credentials private'), and it discloses that the operation yields credentials. It does not address failure modes or retry behavior explicitly, keeping it at a 4.

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?

Two tightly written sentences with zero waste; the prerequisite and core action are front-loaded, and the security note is a fitting closer.

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 mutation tool with idempotent annotations and no output schema, the description conveys the essential workflow and return nature (an API token). However, it leaves the required 'id' parameter unaddressed and gives no guidance on error or retry semantics beyond the schema's idempotency key note, leaving clear gaps.

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 only 33%, with just idempotencyKey documented in the schema. The description alludes to the continuationCredential ('private continuation credential') but leaves the 'id' parameter entirely unexplained and adds no format or constraint detail for the required credential, so it does not compensate for the low coverage.

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 outcome: exchange a private continuation credential for an API token. This clearly distinguishes it from siblings like start_onboarding and onboarding_status, which handle other phases of the flow.

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 phrase 'After owner approval' gives a concrete precondition for when to invoke this tool, which implies it should not be called before approval. However, it does not name an alternative tool or state explicit exclusions, so it stops short of a 5.

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