gmail_forward_message

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

Adds real context beyond the annotations: the forward includes a quoted attribution block, attachments are listed rather than re-attached, and the operation never sends. The annotations already say readOnlyHint=false, destructiveHint=false, and idempotentHint=false, but the description contributes the side-effect shape (a draft, not a send) and the attachment caveat.

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 with no waste: what it does, the two notable behavioural quirks, and the safety caveat. The most important fact (it never sends) is placed where it lands hard.

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?

Covers the mutation-safety question well and explains attachments, but with no output schema the description should say what comes back (draft ID? message ID?) and whether forwarding the same message twice creates duplicate drafts given idempotentHint=false. Those gaps matter for a create 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 description coverage is only 40%, so the description is expected to compensate, and it does not. It says nothing about to/cc/bcc semantics, whether message_id must be a raw Gmail ID versus thread ID, or how comment interacts with the quoted block; the only param-related hint is the attachment behaviour, which maps to no parameter at all.

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: creates a draft that forwards a message, with a quoted attribution block. That is clearly distinct from gmail_reply_with_quote or gmail_send_message_strict in substance, but no sibling is named, so differentiation is inferential rather than explicit.

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?

'Never sends; review the draft before sending' implies the use case (prepare for review rather than send now) and hints that a separate send step follows. It never names an alternative tool such as gmail_create_draft or gmail_reply_with_quote, and gives no exclusions, so usage is only implied.

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