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

The description adds substantial behavioral context beyond annotations: the draft remains unsent and editable, the owner sees it via list_pending_approvals, approval proceeds through approve_and_send, and non-draft UIDs are refused. It is consistent with the non-read-only, idempotent annotations.

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 core action is front-loaded, and each sentence earns its place by covering workflow, persistence, validation, or limitations. Despite covering several points, it remains focused and non-repetitive.

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 single-parameter mutation tool with annotations and no output schema, the description is complete: it explains the state change, workflow position, downstream tool, persistence, and refusal behavior. Nothing necessary for correct invocation is missing.

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 coverage is 100% and the uid parameter is already documented in the schema. The description still adds a meaningful validity condition: the UID must refer to a draft in the Drafts folder, which is beyond the schema's source hint.

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 first sentence gives a specific verb and resource: mark a draft as waiting for owner approval. It clearly distinguishes this tool from siblings by naming approve_and_send, list_pending_approvals, and the drafting tools it follows.

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?

It states exactly when to use it: after draft_reply, draft_forward, or draft_email, for users who cannot send from the mailbox or want owner review. It also names the follow-up tools and the no-send-back limitation, leaving little to inference.

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