Dirtsmith-built free utility: validate JSON data against a JSON Schema subset; returns errors with paths.
| Name | Required | Description | Default |
|---|---|---|---|
| data | Yes | ||
| schema | Yes |
| Name | Required | Description | Default |
|---|---|---|---|
| ok | No | ||
| note | No | ||
| valid | No | ||
| errors | No | ||
| built_by | No | ||
| house_tool | No |
Changes observed during successful MCP inspections.
Output schema / (root)Previous value: -nullNew value: +{
+ "properties": {
+ "built_by": {
+ "type": [
+ "string",
+ "null"
+ ]
+ },
+ "errors": {
+ "type": [
+ "array",
+ "null"
+ ]
+ },
+ "house_tool": {
+ "type": [
+ "boolean",
+ "null"
+ ]
+ },
+ "note": {
+ "type": [
+ "string",
+ "null"
+ ]
+ },
+ "ok": {
+ "type": [
+ "boolean",
+ "null"
+ ]
+ },
+ "valid": {
+ "type": [
+ "boolean",
+ "null"
+ ]
+ }
+ },
+ "type": "object"
+}Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already establish readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds two genuine behavioral facts: the schema support is only a 'subset' (a real limitation to warn about) and errors come back with paths. It does not say whether validation short-circuits or reports all errors at once.
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?
A single well-formed sentence that front-loads the core action. The only dead weight is the 'Dirtsmith-built free utility' vendor tag, which does nothing for tool selection.
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 2-required-param validator with an output schema (so return values need no explanation) and annotations covering safety, the description is nearly adequate. The gap is the unsupported-schema-subset detail and the format ambiguity of 'data', both of which affect whether a call succeeds.
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 0% and the 'data' property is an untyped empty schema, so the description must carry the load. It does map the two required params to their roles (validation payload vs. JSON Schema), but leaves the critical ambiguity of whether 'data' should be a JSON string, an object, or raw text.
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 ('validate JSON data against a JSON Schema subset') plus the output ('returns errors with paths'), which is far more than the name alone conveys. It is trivially distinguishable from all siblings, but the leading 'Dirtsmith-built free utility' promo clause dilutes an otherwise precise statement.
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?
There is no guidance on when to reach for this tool, what prerequisites exist (e.g. which schema dialect/subset must the schema conform to), or when to prefer it over manually checking a payload. The reader must infer the use case from the name.
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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