Check whether a JSON string is valid. Returns parsed object on success.
| Name | Required | Description | Default |
|---|---|---|---|
| api_key_id | No | Your Stripe Customer ID, used for metered billing ($1.00/mo base includes first 100 requests; $0.01 each after). | |
| json_string | Yes | The JSON text to validate. |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHints and idempotentHints, so the description goes beyond by stating the success return value. But it omits behavior on invalid JSON (e.g., whether it throws or returns error), leaving a transparency gap.
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?
The description is exactly two sentences, tightly packaged with the core verb, input, and success return. No filler or redundant restatement of the tool name or schema.
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 validation tool with one required parameter and strong annotations, the description covers the success path and core operation. It could mention the invalid-input behavior, but the tool is simple enough that this is not critical.
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?
The input schema fully describes both parameters, so the description need not elaborate. The description adds no extra meaning beyond what the schema already provides.
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 uses a specific verb ('Check whether') and names the resource ('JSON string'), with a clear success outcome ('Returns parsed object on success'). This distinguishes it from sibling tools like repair_json and sanitize_json_output.
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 usage is implied: use this when you need to verify JSON validity. However, it does not explicitly compare with repair_json or sanitize_json_output, nor state when not to use it.
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.
The three repair tools (repair_json, repair_string, sanitize_json_output) have heavily overlapping purposes. While repair_string has a more detailed description, an agent may struggle to choose between it, the generic repair_json, and sanitize_json_output, which also repairs control characters and removes prose. Only validate_json is clearly distinct.
The names mix patterns: repair_json and repair_string use the 'repair' verb with different objects, while validate_json and sanitize_json_output use other verbs. The object naming is also inconsistent (json, string, json_output). Overall the set is readable but lacks a uniform convention.
Four tools is a reasonable count for a JSON sanity server, fitting within the typical well-scoped range. However, the inclusion of three overlapping repair functions suggests the count could be trimmed without losing core functionality.
The server covers the full lifecycle for its stated purpose: validation (validate_json), repair (repair_json, repair_string), and sanitization (sanitize_json_output). It includes schema validation in repair_string, leaving no obvious gaps in the domain of ensuring JSON sanity.