Create Email Forward

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

Far exceeds what the annotations convey. Annotations only say readOnlyHint=false and destructiveHint=false; the description adds the critical side effect (Porkbun MX records and SPF include are placed at the domain apex), the transactional guarantee ('nothing is changed' on a gated failure), the `DNS_CHANGE_CONFIRMATION_REQUIRED` result with its `dnsChanges` payload, and the user-consent requirement before calling again. This is exactly the mutation context annotations cannot carry.

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 core action and scope, then the side effects and confirmation protocol. It is dense and long, and the bolded confirmation sentence is doing heavy lifting, but every clause is load-bearing for correct invocation; minor trimming of the constraint list is possible.

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 five-parameter mutation tool with no output schema, the description covers the missing return-value story itself: it names the gating error result, its `dnsChanges` field, and the no-op guarantee. An agent has everything needed to call it, interpret the outcome, and handle the confirmation loop.

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%, so baseline would be 3, but the description adds workflow meaning the schema does not: it explains what `confirm_dns_changes: true` is for (only after the user has OK'd the listed DNS changes) and what `dry_run` previews ('including whether confirmation will be needed'). That is value beyond the per-field text.

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 precise verb+resource ('Forward an address at the domain ... to another mailbox') and immediately carves out the domain it is NOT for by listing the disqualifying conditions (catch-all/wildcard, address already an email hosting mailbox). An agent can distinguish it from list_email_forwards, delete_email_forward, create_mailbox and create_url_forward without opening any 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?

Gives explicit when-not conditions ('No catch-all or wildcard forwards, and an address that is an email hosting mailbox cannot also be a forward'), names the exact failure path that requires a second call, and points at `dry_run: true` as the preview mechanism. The routing and prerequisite logic is fully spelled out.

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