update_draft

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It only states 'Update an existing draft message' without revealing whether fields are overwritten independently, what happens to omitted fields, or any permission requirements. This is severely insufficient for a mutation tool.

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, grammatically simple sentence with no wasted words. However, it is under-specified for a tool with 7 parameters, and the brevity comes at the expense of necessary detail. It is concise but not appropriately sized.

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 (7 parameters, mutation operation), the absence of annotations, and the lack of output schema details, the one-sentence description is critically incomplete. It omits parameter semantics, safety/behavioral context, and usage situations, making it nearly useless for an agent to invoke correctly.

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 0%, and the description adds no parameter information. It fails to explain that cc, to, bcc, body, subject are optional and independent fields, or how message_id is used. The description does not compensate for the lack of schema documentation.

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 identifies the action ('Update') and the resource ('existing draft message'). This distinguishes it from sibling creation tools like create_draft_conversation and create_draft_reply, even though it does not explicitly name them.

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?

No guidance is provided on when to use this tool versus alternatives. With over 35 sibling tools including create_draft_conversation and create_draft_reply, the description offers no decision criteria, prerequisites, or exclusions.

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