send_template_email

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

With no annotations provided, the description carries the behavioral disclosure burden. It does add a valuable behavioral detail: variable values are HTML-escaped on substitution, which is safety-relevant for user-supplied text. However, it omits other behavioral aspects such as sending side effects, delivery guarantees, permission requirements, or behavior when a template slug is invalid.

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: two sentences with no filler. The core purpose is front-loaded in the first sentence, and the second sentence adds a genuinely useful safety note. Every word earns its place.

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?

Given 6 parameters, 4 required, no output schema, and no annotations, the description is too thin. It explains the core action and variable escaping, but omits essential operational details like scheduling behavior, required parameter roles, error/response expectations, and when to choose this over sibling tools. An agent would need more information to invoke it confidently in all cases.

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 low at 33%, so the description needs to compensate. It adds one useful semantic fact: variable values are HTML-escaped, informing how the variables object is used. But it does not clarify the format or constraints for from, to, scheduled_at, or how subject override interacts with the template, leaving significant parameter meaning undocumented.

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 ('Send an email') and the resource ('a stored template'), which distinguishes it from the sibling send_email that presumably sends non-template emails. It does not explicitly name the sibling or describe its unique scope, but the template-based nature is specific enough to be useful.

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?

No guidance is provided about when to use this tool versus send_email, send_broadcast, or render_template. The phrase 'built from a stored template' implies the primary use case, but there is no explicit context, exclusions, or alternative routing.

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