Transférer un email

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

With no annotations, the description carries the full burden. It does this well: it states the action is irreversible ('ACTION IRRÉVERSIBLE'), that it actually forwards (not simulates), and mandates user confirmation. These are key behavioral traits. It does not disclose side effects like whether the original email is modified, but for a forwarding action this is minor. Overall it provides substantial behavioral context beyond the schema.

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 two sentences with zero fluff. It front-loads the most critical warning ('ACTION IRRÉVERSIBLE') before stating the purpose, then adds the mandatory confirmation requirement. Every word earns its place, making it both concise and structurally effective.

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?

The description covers the essential context for a mutation tool: irreversibility, the need for user confirmation, and the core action. It does not explain return values or error behavior, but with no output schema and a simple operation, these are not critical for correct invocation. The main practical uncertainty – how to get itemId – is handled by sibling tools. A small gap is not specifying what happens to the original email, but this does not impede usage.

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% – all three parameters (to, itemId, comment) already have clear schema descriptions. The tool description adds no additional meaning for the parameters, so it does not go beyond what the schema provides. Per the rubric, when schema coverage is high, baseline is 3, which is appropriate here.

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 states a specific action: 'transfère réellement un email existant à un nouveau destinataire' (actually forwards an existing email to a new recipient). It clearly distinguishes this from siblings like send_email (creating a new email) and reply_to_email (replying), without needing to open the schema. The verb 'transfère' and resource 'email' are unambiguous.

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 guidance: it is irreversible and the agent MUST always ask for explicit confirmation of the recipient and comment before calling. This is a strong usage constraint that tells when to pause and verify. However, it does not explicitly name alternative tools or state 'use this instead of send_email when forwarding an existing email,' so it misses the explicit sibling differentiation that would earn a 5.

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