Issue a new tenant key and invalidate the current one immediately: every other call using the old key fails as unauthenticated from this point on. Returns the new key exactly once -- use it (as tenant_key or Authorization) for every call after this one.
| Name | Required | Description | Default |
|---|---|---|---|
| tenant_key | No | The key `signup` returned. Required only when this connection carries no Authorization: Bearer header -- when both are present, the header wins. |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the full burden and does so well: it discloses the destructive/irreversible effect (old key fails as unauthenticated immediately), and the one-time-only visibility of the returned key. These are exactly the behavioral traits an agent must know before calling a credential-mutating tool.
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 tight sentences with no filler; the rotation action and its destructive consequence are front-loaded, and the follow-up usage instruction comes second where it belongs. Every clause earns its place.
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?
Given a single optional parameter, no annotations and no output schema, the description covers the return value ('returns the new key exactly once') and the auth contract, which is most of what an agent needs. It omits any authorization prerequisite for calling the rotation itself (e.g. what credential is required to rotate), a minor but real gap for a security-sensitive operation.
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 the single tenant_key parameter is already fully documented, including the Authorization-header precedence rule. The description only adds that the new key works 'as tenant_key or Authorization', which is a marginal restatement rather than new syntactic or format meaning, 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+resource (rotate/issue a new tenant key) and its immediate effect (invalidate the current one), so an agent can tell at a glance that this is a credential-rotation operation. No sibling tool in the list performs key rotation, so no disambiguation is needed.
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 clear post-invocation guidance ('use it as tenant_key or Authorization for every call after this one') and states the consequence of not doing so. It never names an explicit when-to-rotate condition or when-not (e.g. key compromise vs. routine rotation), so it stops short of a full when/alternatives statement.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
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