gmail_update_draft

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

Annotations already declare non-readonly, non-idempotent, non-destructive, open-world, so the safety profile is carried structurally. The description adds two genuinely new facts — that the operation is a full replacement and that it is 'Audited' — but does not explain the audit implication, permission/scope requirements, or what happens to fields omitted from the call.

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?

Three short sentences, front-loaded with the verb and resource, with no filler. 'Audited.' is a bare assertion that earns its place only weakly since it is never explained.

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 9-parameter mutation tool with near-zero schema coverage and no output schema, the description is thin: it never states error behavior (e.g. invalid draft_id), whether draft_id/thread_id must match, or how HTML vs plain body interacts with attachments. It is adequate to start a call but not to call it confidently.

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 only 11% (just the attachments max-5 note), so the description must compensate. It names recipients, subject, body, attachments and is_html but says nothing about cc, bcc, thread_id, or that draft_id identifies the target — leaving over a third of the nine parameters undocumented anywhere.

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 specific verb plus resource ('Replaces a Gmail draft') and enumerates the replaceable fields, which is enough to tell it apart from creation/send siblings. It does not explicitly contrast itself with gmail_create_draft or gmail_get_draft, so differentiation relies on the agent's inference.

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 when-to-use or when-not guidance is given; the agent is not told to prefer gmail_create_draft for new drafts or gmail_send_draft to dispatch one. The word 'Replaces' implies full overwrite but the consequence (existing recipients/subject/body are discarded rather than merged) is left to be inferred.

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