list_recipients

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds the conceptual point that recipients are the underlying mailboxes aliases forward to, but says nothing about ordering, pagination, or result size, which is relevant for a list endpoint.

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?

A single front-loaded sentence with the core purpose first and the clarifying parenthetical second. 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 simple two-optional-parameter list tool with full schema coverage and safety annotations, the description covers what the resource is. Minor gaps remain around result volume and whether the alias count comes back per recipient, but nothing blocks a correct call.

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 both the verified filter and include_alias_count are fully documented in the schema. The description adds no additional meaning about these parameters, so the baseline of 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 gives a specific verb and resource ("List the account's recipients") and disambiguates the term recipient by defining it as the real mailbox an alias forwards to, which separates it conceptually from list_aliases. It stops short of explicitly differentiating against siblings like list_usernames or list_domains.

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 implied by the verb list plus the parenthetical definition, so an agent can tell it's a read-only enumeration of forwarding targets. There is no explicit when-to-use guidance, no mention of when to prefer list_aliases, and no stated prerequisites such as account scoping.

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