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

Annotations already declare destructiveHint=true and readOnlyHint=false; the description adds the concrete state machine (active -> revoked), the authorization requirement, and eligibility exclusions. It does not say whether revocation is reversible or what happens to an already-revoked certificate, but it adds real context beyond the annotations.

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: the state transition is front-loaded, followed by the authorization and eligibility constraints. Nothing is redundant or padded.

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 single-parameter mutation with no output schema, the description covers the state change, who may invoke it, and which certificates are ineligible. It omits idempotency/error behavior for non-active certificates and whether the action is reversible, which is a modest remaining gap.

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 description coverage is 100% and the single parameter already documents that certificate_id is a UUID from create_gift_certificate / list_gift_certificates. The description adds no format, sourcing, or edge-case detail beyond the schema, so 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?

The description states a specific verb ('Revoke'), resource ('gift certificate'), and the exact state transition (active -> revoked). Combined with the precondition about minted/redeemed certificates, an agent can distinguish this from mark_gift_certificate_minted or list_gift_certificates without opening another 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?

It gives explicit when-not conditions ('Already-redeemed/minted certificates cannot be revoked') and a permission constraint ('Only the issuing merchant can revoke'). It stops short of naming the alternative sibling to use when revocation isn't permitted, but the usage envelope is clear.

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