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

No annotations are present, so the description carries the full burden. It discloses merge semantics, auth requirements, operator-only restriction, patron rejection, and the fact that the value is never echoed back. This is far beyond a generic update description.

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?

The description is front-loaded with the core action and then adds focused, non-redundant detail on use case, merge behavior, and security restrictions. It is slightly dense with domain terminology but every section 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?

For a privileged mutation with no output schema, the description covers the invocation-critical points: field-level merge, auth proof, restriction, and non-echoing of the value. It leaves out explicit return or error behavior, but the schema plus security context make successful invocation well specified.

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 input schema already documents all three parameters at high coverage. The description adds useful context, especially for dpop_token as proof, and reinforces that field must be template-declared, adding some meaning beyond the schema.

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 opens with a specific verb and resource: 'Add or update a single operator secret field.' It further distinguishes itself from the full credential-bundle delivery and from patron-oriented tools by stating it is the field-level counterpart and that patron proofs are rejected.

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?

It clearly explains when to use this tool: rotate one secret without restating untouched fields, contrasted with re-delivering the whole bundle over Secure Courier, where omitted fields are destroyed. It signals operator-only usage, though it does not name a specific sibling tool as the alternative.

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