Get email forwarding

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

Annotations already provide readOnlyHint=true and openWorldHint=true, so the read-only nature is known. The description adds a non-obvious behavioral constraint: forwarding only works with Namecheap DNS. This is beyond the annotations and provides useful context. No contradiction exists.

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 two short sentences that cover purpose, scope, a usage condition, and the read-only nature. Every sentence contributes meaning with no fluff or repetition. It is ideally sized for the tool's simplicity.

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?

The tool is simple (one parameter), has an output schema, and read-only annotations. The description includes the essential purpose and an important prerequisite (Namecheap DNS). It omits edge-case behavior (e.g., what happens if the domain is not on Namecheap DNS), but given the tool's minimal complexity, the description is nearly complete.

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 schema has 0% description coverage, and the description does not explain the 'domain' parameter beyond restating 'for a domain' in the first sentence. With a single parameter named 'domain', the description adds no format, example, or constraint beyond what the parameter name and minLength imply. This fails to compensate for the lack of schema descriptions.

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 uses a specific verb ('List') and clearly identifies the resource ('email-forwarding rules for a domain') with the mapping format (mailbox -> destination). It distinguishes itself from sibling tools like set_email_forwarding and get_dns_records by naming a distinct resource.

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 provides a clear usage condition: email forwarding only works while the domain uses Namecheap DNS. It does not explicitly name an alternative tool, but the read-only hint and 'List' verb imply that this is for reading, while set_email_forwarding is the write counterpart. The single constraint gives context, but no direct alternative or exclusion.

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