See how your document will look.
| Name | Required | Description | Default |
|---|---|---|---|
| data | Yes | Template variables as key-value pairs | |
| accept | No | text/html | |
| template_id | Yes | Template ID to preview |
| Name | Required | Description | Default |
|---|---|---|---|
| html | Yes | Rendered HTML preview |
Changes observed during successful MCP inspections.
Input schema / properties / data / descriptionAdded value: +"Template variables as key-value pairs"Input schema / properties / template_id / descriptionAdded value: +"Template ID to preview"Output schema / (root)Previous value: -nullNew value: +{
+ "properties": {
+ "html": {
+ "description": "Rendered HTML preview",
+ "type": "string"
+ }
+ },
+ "required": [
+ "html"
+ ],
+ "type": "object"
+}Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. However, the description adds no behavioral context, such as how the data is rendered, what output formats are supported, or whether it is a stateless preview. It neither contradicts annotations nor enriches them.
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?
While the description is a single concise sentence, it is under-specified rather than appropriately concise. It lacks necessary details and does not front-load actionable information. Every word could earn its place, but here the sentence provides minimal value.
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 the tool has 3 parameters, an output schema, and siblings, the description is incomplete. It does not explain how to provide data, how the accept parameter affects output, or what the preview returns. The annotations and output schema provide some context, but the description fails to tie them together.
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 67% (data and template_id have descriptions, accept does not). The description adds no parameter-specific meaning and does not compensate for the missing accept enum description. It offers no clarification of data structure or expected values beyond the schema.
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 'See how your document will look' is vague and does not state the specific action (preview a template with data) or distinguish it from sibling tools like fill_template or download_pdf. It reads as a benefit rather than a clear purpose, leaving an agent uncertain about the exact operation.
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 given on when to use this tool versus alternatives. There is no mention of prerequisites, context, or when to choose preview over fill_template or download_pdf. The agent is left to infer usage entirely.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
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