update_draft

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

Discloses partial update behavior ('Only provided fields are updated — omitted fields retain their current values'), which goes beyond the destructiveHint annotation. No contradictions.

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?

Two efficient sentences: first states purpose and when to use, second explains behavior and next steps. No waste.

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 12-parameter tool with high schema coverage, the description provides adequate context. Missing mention of return value, but not critical for a mutation tool.

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 92%, so baseline is 3. The description summarizes parameters as 'recipients, subject, body, or other fields' but does not add significant meaning beyond the schema's individual 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 uses the specific verb 'Update' and resource 'existing locally saved draft', clearly distinguishing it from sibling tools like create_draft, send_draft, and delete_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?

Explicitly states when to use ('Use to edit a draft before sending') and provides alternatives for next steps ('call send_draft to send or sync_draft_to_remote to push to Proton Drafts').

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