gmail_reply

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

No annotations are provided, so the description carries the full burden. It only mentions that the reply keeps the thread, but does not disclose whether the reply is sent immediately, requires specific permissions, or any other behavioral traits. For a write operation, more detail is expected.

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 a single sentence with no wasted words. It is concise but not structured with headings or separate sections. The purpose is front-loaded, which is good, but there is room to include brief parameter highlights.

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 (replying to a message), the description covers the core purpose and thread behavior. The schema fully describes parameters, so the missing output schema is less critical. For a basic operation, this is mostly complete, though missing usage context.

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 100%, so the schema already documents all four parameters. The description adds no extra meaning beyond the schema, e.g., explaining how 'replyAll' affects recipients or that 'isHtml' controls formatting. Baseline 3 applies.

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 'Reply to a Gmail message (keeps thread)', specifying the verb (reply), resource (Gmail message), and adding context that the thread is preserved. This distinguishes it from siblings like gmail_send (new message) or gmail_forward.

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 implies usage for replying to an existing thread but does not explicitly state when to use this tool versus alternatives, nor does it provide exclusions or prerequisites. The sibling tools list is extensive, but no guidance is given.

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