reply_all_email

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

Annotations already include destructiveHint: true, and the description adds context by noting threading headers are preserved and that PROTONMAIL_ALLOW_SEND is required. It clearly conveys the immediate sending behavior beyond what the annotation states.

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 concise, with every sentence adding value: purpose, relationship to sibling, when to use, behavior (threading), and a prerequisite. It is front-loaded with the primary action.

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?

Given the tool's complexity (13 params, destructive action, no output schema), the description covers the core purpose, usage context, key behavioral traits, and required permissions. It is sufficient for an agent to correctly select and invoke the 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 coverage is 100% for all 13 parameters, so the schema already documents each parameter. The description does not add additional meaning beyond what the schema provides, placing it at the baseline of 3.

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 tool sends a reply to all original recipients (sender + all To/CC addresses) of an existing email. It distinguishes itself from the sibling reply_to_email by explicitly noting it is identical to reply_to_email with replyAll enabled, making the scope unambiguous.

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?

It provides explicit usage guidance: 'Use when the conversation involves multiple parties and all should receive the reply.' This directly tells the agent when to choose this tool over alternatives like reply_to_email or forward_email.

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