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

Annotations already convey a non-read-only, non-destructive mutation. The description adds that the template is saved and reusable across campaigns, which is useful but does not disclose additional behavioral traits such as idempotency, uniqueness constraints, or required permissions.

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?

Three tight sentences: core action first, a targeted format preference second, and a follow-up workflow step third. Every sentence earns its place with no redundant content.

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?

Since there is no output schema, the description usefully explains that a template id is returned and how to use it in nevent_create_campaign. The relationship between format and body fields is left to the schema, but the schema covers it. The description is adequate for correct invocation.

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%, so the schema already documents all parameters. The description adds meaningful guidance beyond the schema by recommending format='MJML' for responsive email, which helps the agent choose the correct enum value and corresponding body field.

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 verb and resource: 'Create and persist a new email template.' It identifies the content options (MJML or raw HTML) and distinguishes creation from related sibling tools like nevent_update_template and nevent_clone_template.

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?

Clear context is given: use this tool to create a reusable template, prefer MJML for responsive email, and then call nevent_create_campaign with the returned template id. However, it does not explicitly state when to use alternatives like update, clone, or preview.

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