List Forwarders

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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered structurally. The description adds the per-entry shape (alias/local part, full forwarder address, destination addresses), which is helpful context about what is returned, but it largely restates what the output schema already provides and says nothing about volume, pagination, or ordering.

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 sentences, zero filler, with the scope ('all ... on a domain') front-loaded before the return-value detail. Every sentence earns its place.

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 one-parameter read tool with full schema coverage, an output schema, and safety annotations, the description covers purpose and return contents sufficiently. Minor gaps (no mention of result set size or ordering) are low-risk given the output schema and the small, domain-scoped nature of the resource.

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 'domain' parameter is documented in the schema with format constraints (letters, digits, hyphens, at least one dot). The description's phrase 'on a domain' is consistent but adds no meaning beyond the schema, so the 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?

States a specific verb and resource with scope: 'Lists all email forwarders on a domain.' The resource (forwarders) is clearly distinct from siblings like list_email_accounts or list_domains, so an agent can distinguish it, though no sibling is named explicitly.

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?

Usage is only implied by the verb 'Lists' and the domain scoping. There is no explicit when-to-use, when-not-to-use, or reference to an alternative such as create_forwarder or delete_forwarder. For a simple read-only list tool this is adequate, but it leaves routing to inference.

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