create_reply_draft

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

Describes pre-filling behavior and returns a draftId. No annotations provided, so description carries the burden. Could mention permissions or side effects, but it's clear that it creates a 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?

Three concise sentences, front-loaded with the main action. No fluff.

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?

Adequately describes the tool's function and return value. Could elaborate on attachments or cc/bcc, but the schema covers them. No output schema, but mentions draftId return.

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 coverage is 100%, baseline 3. Description adds value by explaining that To, Subject, and quoted body are pre-filled from the original email, which is not in the schema.

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: create a reply draft for a specific email, pre-filling To, Subject, and quoted body. It distinguishes from siblings like create_thread_reply_draft and reply_to_email.

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?

Explicitly says when to use (have emailId, want to stage reply) and when to use alternatives (create_thread_reply_draft for threadId, reply_to_email to send immediately).

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