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

With no annotations, the description carries the full burden and does so: merge semantics (omitted fields untouched, unlike courier replies where omitted fields are destroyed), the value is never echoed back, and the authentication requirement (nsec-signed kind-27235 or cached dpop_token phrase, operator-only) is spelled out.

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?

Front-loaded with the action in the first sentence, then rationale, then auth. Slightly verbose with line-wrapped parentheticals, but every sentence carries distinct information (merge semantics, value echo, auth).

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?

Output schema exists, so return-value explanation is unnecessary; the description covers the mutation scope, auth proof, and the operator/patron boundary. Nothing an agent needs to call this correctly 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?

Schema coverage is 100% and all three parameters are documented there, including that 'field' must be declared in the operator's credential template. The description adds the semantic framing that a *single* field is targeted, but no format or constraint details beyond the schema. 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 ('Add or update a single operator secret field') and immediately frames it as the field-level counterpart to a sibling behavior (re-delivering the whole bundle via Secure Courier). An agent can distinguish it from beesknees_delete_operator_credential, beesknees_update_patron_credential, and beesknees_receive_credentials without opening a schema.

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: rotating one secret (e.g., a reissued btcpay_api_key) without restating unchanged fields. It also names the alternative approach (full bundle over Secure Courier) and the exclusion criterion (patron proofs are rejected), 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.