gmail_reply_with_quote

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

Annotations declare non-readOnly, non-destructive, non-idempotent, open-world, but the description adds the crucial behavior that it never sends and the output is a reviewable draft, plus an audit note. It does not mention required scopes/auth or whether repeated calls create duplicate drafts, which matters given idempotentHint=false.

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 short, front-loaded sentences with zero filler; the quoting behavior, the never-sends guarantee, and the audit note each earn their place.

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 6-parameter mutation tool with no output schema, the description covers purpose and safety well but says nothing about the return value (draft ID?) or thread placement, forcing the agent to infer result handling. Adequate but with clear gaps.

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 only 33% — message_id and comment are documented, but to, cc, bcc, and is_html are bare in the schema, and the description does not clarify them. It also never explains how is_html interacts with the quoted '> ' text, leaving a key ambiguity unresolved.

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?

States a specific verb and resource (creates a reply draft) plus the defining behavior (quoting the original with attribution and '> ' lines), which cleanly separates it from gmail_create_draft and gmail_send_message_strict in the sibling list.

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?

'Never sends; review the draft' sets the usage context clearly and implies the follow-up path to gmail_send_draft. It does not explicitly name alternatives such as gmail_create_draft or state when-not to use this tool, so it stops short of the top score.

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