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

With no annotations, the description carries the full behavioral burden and does so well: it discloses the PENDING state, the returned one-tap approval_url, that nothing is mailed until Allow, and that on_command keys may auto-send within guardrails. It leaves out edge behavior such as denials, expiry, or repeated calls on the same draft.

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 core action is front-loaded in one sentence, followed by a compact tier-keyed breakdown. Every clause carries information; only the formatting is slightly unusual for a tool description.

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?

An output schema exists, so the approval_url and status fields need not be re-explained, and the remaining non-obvious behavior (pending vs auto-send) is fully covered. Only failure/retry semantics are absent, which is a minor gap for a two-parameter submission tool.

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% (api_key format lms_..., draft_id origin from draft_letter), so the schema already documents both parameters. The description adds no format, constraint, or example beyond what the schema provides, making the baseline 3 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 states a specific verb and resource: requesting that a draft be mailed, scoped to a draft_id. It implicitly separates itself from send_status (this initiates, that reports), but never names its siblings, so the differentiation must be inferred.

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 explains what happens under two key tiers, which is behavioral rather than selection guidance. It gives no explicit when-to-use-this-vs-draft_letter/send_status rule or prerequisite ordering, so usage is only implied.

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