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

No annotations are provided, so the description must carry the full burden of behavioral disclosure. The description notes that placeholders are substituted at send time, which helps set expectations, and mentions the subject required, but it does not explain side effects (e.g., whether the template is immediately usable, any validation, or default behaviors). It lacks details on possible errors or the return format beyond the id.

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 concise and front-loaded with the core action. It uses two sentences to cover the main points: placeholders and required subject, ending with the return. There is little waste, though the first sentence could be slightly more explicit about the resource type for better scoping. Overall, it is efficient and readable.

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 that the tool is simple (3 params, no output schema, no nested objects), the description is adequate. It covers the essential call details: placeholders, required subject, and return id. However, it lacks information about error handling, any side effects, or validation rules, which an agent might need in edge cases. The absence of annotations increases the need for such detail, so the description is minimally sufficient but not comprehensive.

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%, so the schema already describes each parameter (body, name, subject). The description adds value by specifying that subject is required and that placeholders are used, but does not go beyond the schema's own descriptions. Since schema coverage is high, baseline is 3, and the description provides marginal additional context (e.g., that variables are substituted automatically).

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 ('Create') and the resource ('EMAIL template'), and highlights that it is specifically for email templates, distinguishing it from SMS templates (sibling tools include sms_templates_create). It lists the required fields (subject) and placeholders, making the purpose precise and 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 does not explain when to use this tool versus alternatives like email_templates_update or sms_templates_create. It does not mention exclusions or prerequisites, such as needing an existing template or the context for email vs sms. The differentiation from SMS is implied by the resource name but not explicitly stated.

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