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

No annotations are provided, so the description carries the full burden. It discloses that the tool sends via Resend, marks sent, records sent_at and resend_message_id, and honors suppression lists. It also mentions outbound-tier approval requirements. However, it does not describe error behavior, idempotency, or what happens if the send fails, which would be valuable for a mutation tool.

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 description is compact with six sentences plus a routing section and a note. It is front-loaded with the core action. The additional information (suppression list, approval note) is valuable and not redundant. A slight reduction in length could be possible, but it remains focused.

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 that there is no output schema and no annotations, the description covers the tool's purpose, when to use it, approval context, suppression list, and required parameters. It lacks details about the response or error states, but for a straightforward send action, it provides sufficient context for an AI agent to use it 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?

Schema description coverage is 100%, with each parameter already having a clear description in the schema. The tool description reinforces that draft_id is for a single lead_drafts row but does not add significant new meaning beyond the schema. Baseline 3 is appropriate.

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 action ('Send'), the resource ('approved outreach draft'), the target ('to its lead via the company's Resend connection'), and the additional effect ('mark the draft sent'). It also distinguishes from siblings like 'send_email' by specifying it operates on a single lead_drafts row and is a human-in-the-loop operation.

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?

The description explicitly states when to use the tool: 'Use after an operator approves a draft in the Leads tab' and includes a routing section that says 'Operator approved an outreach draft and wants to send it → use this'. It also notes the do_not_contact suppression list and the outbound-tier approval requirement, providing clear context. However, it does not explicitly list alternative tools or when not to use it beyond suppressed leads.

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