Create reusable HTML templates with merge variables to personalize and standardize letter content for multiple mailings.
Create an HTML template with Handlebars merge variables (e.g., {{name}}, {{address}}). Templates can be reused across multiple letters.
| Name | Required | Description | Default |
|---|---|---|---|
| html | Yes | HTML content with optional {{mergeVariable}} placeholders | |
| description | No | Template description/name for easy identification |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are present, so the description carries the disclosure burden. It reveals that the template is persistent/reusable and that Handlebars variables are substituted, but it does not describe validation, return values, side effects, or failure behavior. This is adequate but not rich.
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?
Two sentences, front-loaded with the action and resource, with no filler. The sentence about reuse earns its place by adding useful context.
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 simple two-parameter create operation with full schema coverage, the description is sufficiently complete to drive a correct invocation. It does not explain response/return data, but no output schema exists and that is less critical here.
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 baseline is 3. The description adds concrete Handlebars variable examples, but the schema already documents the placeholder behavior; no additional parameter constraints or format rules are provided.
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?
States a specific verb and resource: 'Create an HTML template', and adds Handlebars and letter-reuse context. This clearly distinguishes it from sibling tools like postgrid_create_letter, postgrid_update_template, and postgrid_get_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?
Gives clear context by noting templates can be reused across multiple letters, implying use when a reusable template is needed rather than a one-off letter. It does not explicitly mention alternatives such as update_template for editing existing templates, so it stops short of a 5.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.