reply_to_message

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

With no annotations, the description carries the full burden and discloses the important two-phase commit behavior ('Previews first and sends on the second call'). It also explains reply_all recipient behavior and thread preservation. It does not detail side effects of preview or whether the first call mutates anything, but the core behavioral contract is clear.

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 sentences with no filler. The core purpose is front-loaded, and the second sentence packs the critical workflow detail into a compact reference to send_message.

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 10-parameter tool with no annotations and no output schema, the description is too thin. It does not explain what the preview response contains, how to obtain or interpret confirmation_token, which message uid refers to, or what the final send returns. The reliance on 'exactly like send_message' is helpful but not self-contained.

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%, so the description must compensate, but it only explains reply_all, commit, and confirmation_token. The other seven parameters (uid, body, folder, account, html_body, attachments, quote_original) receive no explanation and are not obviously inferred from the description alone.

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 ('Reply'), a specific resource ('a message'), and a key scoping detail ('keeping the thread intact'). It also distinguishes itself from send_message by specifying recipient behavior ('Goes to the sender only unless reply_all=True').

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?

Provides clear operational guidance: preview first, then send with commit=True and confirmation_token. The 'exactly like send_message' reference strongly implies a shared workflow, but does not explicitly state when to choose this over alternatives like send_message or create_draft for new emails.

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