Retrieve a value from JSON or JSONC data using a jq-like path from a local file or inline string. Works offline without external requests.
Get a value at a jq-like path (e.g. .foo.bar[0]). Local files/strings only. Does not fetch URLs or contact external services.
| Name | Required | Description | Default |
|---|---|---|---|
| path | Yes | Path like .a.b[0] | |
| text | No | Raw JSON/JSONC string (alternative to filePath). | |
| filePath | No | Local JSON/JSONC file path. |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full behavioral burden. It discloses that the tool is local-only, reads rather than modifies, and has no external network interaction. It does not describe behavior when the path is missing or input is invalid, but for a simple getter this is a minor 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?
Two concise sentences convey the purpose, path syntax, accepted input sources, and key limitation. No filler or repetition.
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 low-complexity tool with no output schema, the description covers purpose, input scope, and safety-relevant behavior. It is complete enough for an agent to call it correctly, though edge-case behavior on missing paths or malformed JSON is not specified.
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 100%, so the schema already documents path, text, and filePath. The description adds 'jq-like' semantics and 'Local files/strings only,' which reinforces but does not substantially extend what the schema already states.
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 a specific verb ('Get'), a specific resource ('a value at a jq-like path'), and gives a concrete path example. This clearly distinguishes it from reading sibling tools like validate_json, json_set, pretty_json, and diff_json.
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: this tool reads values from local JSON/JSONC strings or files, and explicitly says it does not fetch URLs or contact external services. It does not explicitly name sibling tools as alternatives, but the extraction use case is obvious enough to guide selection.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.