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

Beyond the annotations (destructiveHint, idempotentHint), the description details concrete behaviors: signing links stop immediately, non-signers are emailed, and the send credit is returned only if nobody opened the envelope. This adds valuable context about side effects and conditions, fully leveraging the opportunity to disclose behavior.

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 three short sentences, front-loading the purpose first, then adding essential side effects. No waste, no redundancy, and every sentence contributes to understanding.

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?

The description covers the core purpose and side effects effectively, and since an output schema exists, return values are covered elsewhere. However, it omits any guidance on the reason parameter and does not clarify whether the envelope document itself remains accessible. Given the tool's destructive nature, this is a minor but noticeable gap.

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?

With schema description coverage at 0%, the description must explain the parameters but does not mention document_id or reason at all. It provides zero insight into what these parameters represent or how to use them, leaving the agent to infer from names alone. This is a major gap.

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 'Void a sent envelope so it can no longer be signed' — a specific verb, resource, and outcome that distinguishes it from siblings like send_envelope and get_envelope_status. The purpose is unambiguous and actionable.

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 specifies the condition 'sent envelope', indicating it applies to already-sent envelopes, which provides clear context for when to use it. However, it does not explicitly contrast with alternatives or mention when not to use it, so it falls short of the highest tier.

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