ack_verify_credential

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

With no annotations present, the description carries the full burden and does well: it discloses the checks performed (signature, expiration, trusted issuers), the did:key limitation, and the return shape {valid: true/false}. It stops short of describing error behavior or whether validation failures throw vs return false, but the boolean return makes this mostly inferable.

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 concise sentences front-load the core action, then cover key checks, optional behavior, a critical limitation, and the return value. Every sentence adds distinct value with no redundant restatement of the tool name or schema.

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 no output schema and no annotations, the description adequately covers purpose, parameters, constraints, and return shape. Slight gaps around error handling and explicit prerequisites (e.g., needing a resolved DID document) prevent a perfect score, but the tool is callable correctly from the description alone.

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%, so the baseline is 3, but the description adds behavioral meaning beyond the schema: it explains that trustedIssuers restricts allowed issuers and that verifyControllerClaims requires controller-supporting DID methods. This enriches the parameter semantics beyond property names and types.

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 action ('Verify'), a specific resource ('signed credential JWT'), and names its producer ('from ack_sign_credential'), which clearly distinguishes it from sibling tools like ack_verify_jwt or ack_verify_payment_receipt. The scope of verification (signature, expiration, trusted issuers) is also explicit.

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 description implies when to use the tool by tying it to ack_sign_credential and explains when the optional controller verification is viable or not (did:web vs did:key). It does not explicitly contrast with ack_verify_jwt or state when not to use this tool, but the context is reasonably clear.

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