format_jsonValidate JSON and pretty-print, minify, or sort its object keys, returning the error position when parsing fails so you can fix malformed data quickly.
Validate JSON and pretty-print or minify it, optionally sorting object keys. Returns the error position for invalid JSON.
| Name | Required | Description | Default |
|---|---|---|---|
| json | Yes | The JSON text | |
| indent | No | 2 | |
| sortKeys | No |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already establish that this is read-only, non-destructive, and closed-world. The description adds useful behavior beyond that by stating it validates JSON and returns error position for invalid input.
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 short sentences front-load the core action and add only relevant behavior. There is no redundant or filler content.
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 utility with no output schema, the description covers the main actions, optional sorting, and invalid-JSON error behavior. It could be slightly more complete by mentioning the indent choices, but annotations and schema cover the safety profile and enum values.
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 low at 33%, so the description should compensate. It does explain pretty-print/minify and optional key sorting, mapping to indent and sortKeys, but it does not explain the indent enum values or defaults, leaving some schema-derived detail implicit.
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 states specific verbs and resource: validate JSON, pretty-print, minify, and optionally sort keys. It clearly distinguishes this utility from unrelated siblings such as hash_text or convert_timestamp.
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 gives clear context for when to use the tool: validating and formatting/minifying JSON, with optional key sorting. No relevant sibling competes for this task, but there are no explicit exclusions or alternative guidance.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.