Create draft

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

Annotations already declare this is a non-destructive write with openWorld and non-idempotent behavior. The description adds genuinely new context beyond them: the draft is persisted to the Drafts folder and sending is deliberately left to the user elsewhere, which shapes how an agent should sequence its work.

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 compact sentences, with the core action stated first and the non-send guarantee immediately after. Every sentence carries information.

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 six-parameter creation tool with a fully documented schema and no output schema, the description covers purpose and the crucial send-vs-save behavior. It is slightly short of complete because it says nothing about what the tool returns (e.g., a draft identifier) or what happens when a draft with the same subject exists.

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 all six parameters including the optional account, cc, and bcc are already explained in the schema. The description adds no parameter-level detail, so the baseline of 3 is appropriate.

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 gives a concrete verb and resource ("Writes a new email and saves it to the mailbox's Drafts folder") rather than merely restating the title. "New" implicitly distinguishes it from the draft_reply sibling, though that sibling is never named.

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 clarifies the outcome (nothing is sent; the user sends from webmail or their mail app), which implies when to choose this tool. However, it never explicitly names the alternative draft_reply or states conditions for choosing one over the other.

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