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

Annotations only provide false flags for readOnly, idempotent, and destructive, which are minimal. The description adds critical behavioral details: the transfer costs exactly twice the initial purchase value, the serial number and hash remain unchanged, and the transfer takes effect only after payment via a returned payment link. This goes far beyond the annotations and fully discloses the operation's side effects.

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 primary action and then provides essential operational details: the pricing rule, the unchanged identifiers, and the payment/effect timing. Every sentence serves a purpose, including the historical clause which explains the cost rationale. It is compact and well-structured.

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?

This is a 3-parameter tool with no output schema, yet the description covers the action, the cost, the non-reissuance of the certificate, and the post-payment activation. There are no obvious gaps that would prevent an agent from selecting and invoking the tool correctly.

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 covers all three parameters with descriptions, so the baseline is 3. The description adds extra meaning by clarifying that the cost is tied to the certificate's initial purchase value (relevant to order_id) and reinforcing that the new_bearer_email is where the endorsed certificate is sent. This supplemental context enhances parameter understanding 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 'Pass a certificate to someone else,' using a specific verb and resource that clearly identifies the action. It further distinguishes from siblings by stating it is the same object endorsed to a new bearer, not a new certificate, which differentiates it from create/order/cancel operations.

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?

Clear context is provided: the tool transfers a certificate to a new bearer, with an explanation of the double-cost rule and the payment-link flow. It does not explicitly name alternative tools or state when not to use it, but the use case is unambiguous.

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