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

Annotations establish the write/idempotency profile but say nothing about invalidation scope or secret handling; the description fills exactly that gap — the old credential and its child tokens are invalidated, and the new secret is returned only once. That 'shown once, store it now' warning is the single most actionable behavior for an agent.

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 sentences, each load-bearing: what changes, what is required, what comes back. The destructive consequence is front-loaded and the storage warning is last, which is the right ordering.

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?

With no output schema, the description carries the full return-value burden and does so ('Returns the new credential once'). For a zero-parameter, high-consequence operation, nothing an agent needs before calling 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?

The tool takes zero parameters, so the baseline is 4 and there is no schema content to duplicate. The description still adds credential-context semantics (which credential type may invoke it), which is useful framing rather than parameter documentation.

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 ("Replace the current bootstrap credential and invalidate it and its child tokens") plus the observable effect, which behaviorally separates it from revoke_credential. It never names that sibling or any alternative, so it falls short of the explicit differentiation a 5 requires.

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?

Gives concrete preconditions: an agent must be on the credentials scope and hold a bootstrap credential, not a short-lived token. It also tells the agent to persist the returned value before subsequent calls. It stops short of explicitly contrasting rotation with revocation or stating when rotation is the right choice.

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