Validate data using a bounded JSON Schema 2020-12 subset. FREE during validation. No key, credits or wallet. Existing source and input limits apply.
| Name | Required | Description | Default |
|---|---|---|---|
| input | Yes | ||
| requestId | No | Optional legacy field; ignored in free mode. | |
| maxPriceMicroUsd | No | Optional legacy field; ignored in free mode. |
| Name | Required | Description | Default |
|---|---|---|---|
| scope | Yes | ||
| valid | Yes | ||
| issues | Yes |
Changes observed during successful MCP inspections.
Input schema / properties / maxPriceMicroUsd / descriptionPrevious value: -"Explicit maximum new debit; 0 means recovery only."New value: +"Optional legacy field; ignored in free mode."Input schema / properties / maxPriceMicroUsd / maximumRemoved value: -999999999999Input schema / properties / requestId / descriptionPrevious value: -"Persist the ID returned by agent_utilities_prepare. Reuse after uncertainty."New value: +"Optional legacy field; ignored in free mode."Input schema / properties / requestId / patternRemoved value: -"^\\d{13}_[A-Za-z0-9_-]{16,80}$"Input schema / requiredPrevious value: -[
- "input",
- "requestId",
- "maxPriceMicroUsd"
-]New value: +[
+ "input"
+]Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare the safety profile (readOnlyHint=true, destructiveHint=false, openWorldHint=false). The description usefully adds that validation runs against a 'bounded JSON Schema 2020-12 subset' and that existing source/input limits apply, but it never says which subset or what the limits actually are, so the added context is directionally useful but vague.
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?
Four short sentences with the core purpose front-loaded, and no sentence is obviously padding. The repeated free/pricing framing ('FREE during validation' plus 'No key, credits or wallet') is slightly redundant but compact.
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?
An output schema exists, so return values need not be explained. However, for a validator the unsupported portion of the 'bounded subset' is exactly the information an agent needs to avoid misusing it, and neither the subset boundaries nor any usage routing are provided.
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 only 67% and the description adds no parameter-level detail: it never explains the required nested schema/data pair or the semantics of the two legacy fields. The 'no key, credits or wallet' line only loosely corroborates that requestId and maxPriceMicroUsd are ignored, which is already stated in 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?
States a specific verb (validate) and resource (data using a bounded JSON Schema 2020-12 subset), which is clear and actionable. It does not explicitly distinguish itself from siblings like contracts_openapi_lint or data_json_diff, so it stops short of a 5.
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 spends its guidance budget on pricing (FREE, no key/credits/wallet) rather than on when to choose this tool over alternatives. There is no stated when-to-use, when-not-to-use, or named alternative among the many sibling validation tools.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.