List Scheduled Sends

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds valuable context: it returns only messages with status 'pending' or 'sending', orders them by scheduled send time, and mentions the returned id can be used for cancellation. This goes beyond the annotations without contradicting them.

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 with no fluff. The main purpose is front-loaded, the return behavior and ordering are stated, and the cancellation cross-reference is included. 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 read-only listing tool with two optional parameters and an output schema, the description is complete. It covers what is returned (statuses, ordering), optional filtering, and how to act on results (cancel). The output schema handles return details, and the annotations handle safety.

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 coverage is 100%, so both parameters are well-documented in the schema. The description reinforces inbox_id by saying it filters by inbox, which mirrors the schema description. It does not add new meaning for the limit parameter, but the baseline is 3 given full coverage.

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 states a specific verb (list), resource (pending scheduled email sends), and scope (workspace). It clearly distinguishes from siblings like 'schedule' (which performs actions) by focusing on listing and explicitly mentioning the statuses and ordering.

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 context on when to use: to list pending sends, optionally filtered by inbox. It also explicitly directs the agent to the 'schedule' tool with action 'cancel' for stopping a send, offering an alternative path. This is explicit usage guidance with a cross-reference.

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