yahoo_forward_mail

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

With no annotations present, the description carries the full burden and does reasonably well: it discloses the critical draft-vs-send behavior (send_now default False saves to Drafts), the default source folder, the default account resolution (accounts.json), and that additional_text is plain text prepended above forwarded content. It omits auth requirements, rate limits, and whether the source message is modified.

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 purpose is front-loaded in one sentence, followed by a clean per-argument list. It is slightly padded by the 'Returns' line, which duplicates the existing output schema, but overall it is tight and easy to scan.

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 an 8-parameter mutation tool with no annotations, the description covers every argument's meaning and defaults, plus the draft/send behavioral split. Because an output schema exists, the return-value sentence is a minor bonus rather than a necessity, and nothing an agent needs to call it correctly 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 0%, so the description must compensate, and it does for all 8 parameters: msg_id provenance, comma-separated recipient syntax, cc/bcc roles, additional_text format and placement, folder default, send_now semantics, and the account key format with its default. This fully closes the schema gap.

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 ('Forward an existing message'), plus a distinguishing trait ('preserving attachments'). This separates it from the sibling yahoo_send_mail, which composes a new message rather than forwarding an existing one.

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 implies usage by tracing msg_id back to yahoo_list_mail / yahoo_search_mail and by explaining that send_now=False yields a draft rather than a dispatch. However, it never explicitly says when to choose this over yahoo_send_mail or what prerequisites (auth via yahoo_check_auth) are needed.

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