Update email draft

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

With no annotations, the description carries full behavioral burden. It usefully discloses that the operation replaces the draft contents rather than patching them, but it does not cover permissions, whether omitted fields are cleared, or the return behavior.

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?

A single sentence with zero waste, and the key replacement behavior is front-loaded. It is appropriately sized for the core 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?

For a 13-parameter mutation tool with no annotations and no output schema, the description is minimal. It conveys the main operation but omits side-effect details, prerequisites, and return-value expectations that an agent might need.

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 baseline is 3. The description lists recipients, subject, body, and attachments but adds no syntax, format, or default information beyond what the schema already provides.

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 uses a specific verb ('Replace') and resource ('contents of an existing draft') and enumerates the main replaceable fields. It distinguishes itself from siblings like google_gmail_drafts_create and google_gmail_drafts_send by emphasizing existing draft replacement.

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 phrase 'existing draft' implies the tool is for modifying, not creating or sending, but no explicit when-to-use or alternatives are named. The agent must infer that drafts_create and drafts_send are different operations.

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