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

With no annotations, the description carries the full behavioral burden and does well: it states that only the last message is forwarded, the text is quoted under its own header, and carried files are reattached. It also discloses that the recipient's answer creates a separate thread, though it omits permissions, failure behavior, and whether the original thread 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 description is two tightly written sentences with no filler, and the core action is front-loaded. The second sentence adds useful routing context without bloating the definition.

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 five-parameter mutation tool with no annotations and no output schema, the description covers the key mechanics: what is forwarded, how it is quoted, attachment handling, and the new-thread consequence. It leaves some behavioral gaps around permissions and error handling, but the essential call context is present.

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%, and the schema already explains all five parameters in detail, including cc, bcc, note, and conversation_id. The description adds forwarding behavior but does not add parameter-specific semantics beyond what the schema provides, so the baseline 3 is appropriate.

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 uses a specific verb and resource: it passes the last message of a thread on to someone else, and it clarifies that the recipient's answer opens a new thread. That behavioral contrast distinguishes forwarding from replying and makes the tool's purpose identifiable without opening the schema.

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 gives a concrete usage context: forwarding to the account support address is how a message reaches the support queue, and notes that this works in that direction only. It does not explicitly name alternatives such as reply_to_conversation or send_email, but the support-queue scenario makes the intended use clear.

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