forward_email

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

With no annotations, the description carries the burden of disclosing behavior. It states the tool forwards immediately, preserves original attachments, and prepends an optional note. It does not mention side effects (e.g., whether the original email is marked as forwarded) or limitations (e.g., recipient caps, size limits). The permission requirement adds transparency, but some behavioral details are missing, earning a 4.

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 description is extremely concise at two sentences, yet it covers the core action, key features, and alternative tool. Every sentence is purposeful with no fluff or redundancy.

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?

Despite complex parameters (7 params, nested objects) and no output schema, the description omits what the tool returns (e.g., forwarded email ID or status). It also does not mention error handling or rate limits. While the description is clear for usage, the lack of return value information makes it less complete for agent decision-making. An output schema would help, but since it's absent, the description should compensate.

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?

All parameters have schema descriptions (100% coverage). The description adds value beyond the schema by clarifying that original attachments are automatically preserved (the schema's 'attachments' parameter is for adding new ones) and that 'body' is an optional note prepended. This extra context helps the agent understand parameter usage beyond field definitions.

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 clearly states the action: 'Immediately forward an existing email to new recipients' and specifies key details like preserving attachments and prepending a note. It also explicitly distinguishes this tool from 'create_forward_draft' by noting when to use each, providing strong differentiation among siblings.

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?

The description gives explicit when-to-use guidance ('when you have an emailId and want to re-route the message without review') and when-to-use-an-alternative ('Prefer create_forward_draft to stage a forward for review first'). It also mentions a required permission ('Requires PROTONMAIL_ALLOW_SEND'), offering practical usage advice.

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