update_draft

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

Annotations already declare destructiveHint=true, readOnlyHint=false, and non-idempotency, so the safety profile is covered. The description adds genuine extra context by explaining that the revision is used for optimistic concurrency ('to prevent lost edits'), but it omits the failure mode when the revision is stale and the fact that the entire draft is overwritten.

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 front-loaded sentence with no wasted words, and the concurrency rationale is embedded efficiently rather than padded out.

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 destructive mutation with three required parameters, a nested message object, and no output schema, the description is too thin. It does not say what happens on a revision conflict, whether the replacement is total, or how the nested message payload relates to the existing draft.

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% for the top-level parameters, so the description carries the burden. It clarifies the purpose of 'revision' but says nothing about 'draftId' or the complex nested 'message' object (to/subject/html/attachments), leaving most parameters unexplained.

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?

States a specific verb and resource ('Replace a local draft'), which distinguishes it from the create_draft/delete_draft siblings. However, it does not name an alternative directly, and 'Replace' versus the tool name 'update_draft' creates mild ambiguity about full-replacement vs partial-update semantics.

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?

There is no when-to-use guidance or routing to siblings such as create_draft or get_draft. The clause about 'current revision' hints at a concurrency workflow but does not tell the agent when to prefer update over create or what to do first.

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