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

With no annotations, the description carries the burden and usefully discloses the key side effect that the send will actually go out because it has already been approved, and that send_at="now" sends immediately. It still omits permission requirements and error behavior, so it is not fully transparent.

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?

It is short and front-loaded: the core action and side effect appear before argument details, with no unnecessary filler beyond the response label.

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-parameter mutation, it covers purpose, both parameters, the key side effect, and success response. It lacks error cases and detailed return information, but no output schema exists.

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 0%, so the description must compensate; it defines both required parameters, including where the handle comes from and that send_at accepts "now" or ISO-8601 with an example.

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?

Names a specific action and resource: rescheduling a pending send to a different time. This clearly differentiates it from siblings like list_scheduled, cancel_scheduled, and approve_draft.

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 implies usage for an already approved pending send and points to list_scheduled or approve_draft as handle sources, but it does not explicitly say when to use cancel_scheduled or the schedule_* tools instead, nor when not to use this tool.

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