Save or update a Gmail draft 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 explains that quoteOriginal appends Gmail-style quoted parent history and appendSignature appends the account signature, adding some behavioral context. However, it does not disclose side effects (e.g., overwriting existing drafts), authentication needs, or rate limits.

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 at two sentences, with the first sentence front-loading the purpose. Every sentence adds value, and there is no redundancy or fluff.

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 12 parameters, no output schema, and no annotations, the description is insufficient. It does not explain the purpose of many parameters (cc, bcc, html, accountAlias, chatScope), nor the return value or side effects. A more complete description would cover all parameters and expected output.

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?

With schema description coverage at 0%, the description adds meaning for 4 parameters (format, quoteOriginal, appendSignature) but leaves 8 parameters unexplained, including the confusing 'html' parameter and the 'body' parameter (which it says is required but is not in schema). It partially compensates for the lack of schema descriptions.

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 'Save/update a Gmail draft reply for a thread without sending.' It specifies the verb (save/update) and resource (Gmail draft reply), and distinguishes from sending tools among siblings. However, it does not explicitly differentiate from other draft-related siblings like fetch_drafts or multi_gmail_set_draft.

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 mentions 'without sending' implying when to use, but it inaccurately lists 'body' as required when the schema only requires messageId, to, and subject. It provides no explicit guidance on when not to use this tool or alternatives, such as when to use send or fetch_drafts instead.

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