preview_template

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

With no annotations provided, the description effectively communicates that the tool is non-destructive (does not send) and returns the resolved subject and body. It could mention potential behavior for invalid template IDs or missing variable handling (though missing variables are documented in 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 a single sentence that is direct and front-loaded with the key verb and purpose. Every word contributes to understanding, with no filler or repetition.

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 preview tool with no output schema, the description adequately specifies what is returned (subject and body) and that nothing is sent. However, it does not mention possible error conditions or how failures are reported, which could be useful for completeness.

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 100%, and the description adds minimal extra meaning beyond the schema descriptions for the `variables` parameter (e.g., 'sample variables'). The schema already explains missing variables, so the description does not significantly enhance understanding.

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 ('Render'), the resource ('saved template'), and the output ('resolved subject and body'), while explicitly differentiating from sending by saying 'without sending anything'. This distinguishes it from sibling tools like `send_email`.

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 implies usage for previewing templates before sending, but does not explicitly state when to use versus alternatives, nor does it provide exclusion criteria. The phrase 'without sending anything' offers some guidance but is not comprehensive.

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