mail_reply

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

With no annotations, the description must carry the full burden of behavioral disclosure, but it only states 'Reply to an email in Outlook.' It fails to mention whether the original message is included, if attachments are handled, or what the output looks like. The lack of annotation placeholder suggests this is a deliberate omission.

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 extremely concise, consisting of a single sentence with no redundant words. However, it is perhaps too brief, lacking details that could be added without sacrificing conciseness.

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 simplicity and the presence of an output schema (indicated but not shown), the description provides minimal but adequate context for a developer familiar with email APIs. However, it omits common details like reply format (plain text vs HTML) and how to obtain the message_id.

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?

The input schema covers 100% of parameters with descriptions, so the baseline is 3. The description adds no extra semantic value beyond the schema; it merely confirms the tool's purpose, which the schema already implies.

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 specifies the verb 'Reply' and the resource 'an email in Outlook', making the tool's function unambiguous. It effectively distinguishes from sibling tools like mail_send (send new email) and mail_read (read), which have different purposes.

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 provides no guidance on when to use this tool versus alternatives like mail_send or reply-all variants. It does not mention prerequisites such as needing a valid message_id from mail_list or mail_search, nor does it explain the reply behavior (e.g., reply-to-sender vs reply-all).

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