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

With no annotations provided, the description carries the behavioral disclosure burden and does so reasonably well: it explicitly marks the operation as read-only, explains the paid-plan prerequisite for launching managed senders, and clarifies the managed-mode capacity meaning. It does not cover authentication details, rate limits, or full response shape, but it discloses the key behavioral constraints.

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 definition is dense and front-loaded: it names the resource, summarizes returned fields, explains key summary values, states the paid-plan requirement, specifies id usage, and marks read-only status without filler. Every clause carries practical information.

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?

Given the tool has no parameters, no output schema, and no annotations, the description supplies substantial context: returned fields, summary keys, capacity interpretation, paid-plan gating, and intended use of ids. It is not fully exhaustive about the return structure, but it is complete enough for an agent to invoke and interpret the tool correctly.

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 tool has zero parameters, so parameter semantics are not applicable and the baseline is 4. The description appropriately focuses on output fields and usage context rather than inventing parameter semantics.

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 clearly states the resource and scope: sending addresses available to this workspace, including managed pool and own mailboxes, with specific fields such as warm-up level, daily limit, and status. It is specific enough for an agent to understand what the tool returns, though it does not explicitly differentiate itself from related siblings like get_sdr_email_capacity or list_client_mailboxes.

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 provides clear usage context: managed senders require a paid plan to launch, and returned ids should be used in settings.senderEmailIds. However, it does not state when to prefer this tool over related capacity or mailbox-listing tools, so the guidance is contextual but not alternative-aware.

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