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

Annotations already declare destructiveHint=true, openWorldHint=true, and readOnlyHint=false, so the agent knows this is an irreversible external-facing write. The description adds genuine value beyond that by imposing an owner-approval precondition, which no annotation conveys. However, it does not describe what actually happens on send (channel, whether the draft is consumed/locked, cost, failure handling).

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 short sentences with zero filler, and the action statement is front-loaded before the conditional gate. Nothing could be removed without losing 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?

For a one-parameter, destructive, open-world action, the definition covers the essential safety gate and the identity of the target resource. The remaining gap is outcome information: with no output schema, the description never indicates whether the tool returns a delivery confirmation, an error, or nothing at all.

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%, but the single parameter is fully constrained by type/format/pattern (uuid) and required-ness, so the syntax burden is already carried by the schema. The description contributes meaning by implying draft_id must reference an already-approved draft, but offers no guidance on where that id comes from or what happens with a stale one.

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 pairs a specific verb ('send') with a specific resource ('a draft'), and adds the constraint that the draft must be an owner-approved one. It implicitly distinguishes itself from the drafting sibling draft_text by implying the draft already exists, though it never names that sibling or clarifies the channel (text/SMS) despite the tool name and title.

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?

'Only call after the owner says send' is an explicit, actionable gate that tells the agent precisely when invoking is appropriate. What is missing is the negative case and alternatives: other send tools (send_estimate, send_invoice, send_pay_link) are siblings and the description gives no rule for choosing among them, nor does it say what to do if the owner has not yet approved.

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