Extract values from JSON, YAML, TOML, CSV, XML, or PSD1 files using path expressions such as servers[0].name or users[*].email; returns matching values as JSON.
Extract values from a json/yaml/toml/csv/xml/psd1 file with a path expression such as 'servers[0].name', 'users[].email' or '.port'. Returns JSON (a list of matches).
| Name | Required | Description | Default |
|---|---|---|---|
| path | Yes | ||
| query | Yes | ||
| format | No |
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden. It does disclose the return shape ('Returns JSON (a list of matches)') and the supported input formats, but it never states that the file is only read and not modified, nor how it behaves on non-matching paths or malformed 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 tight sentences, front-loaded with the verb and resource, with examples inline and the return type stated at the end. No wasted text.
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 read-only extraction tool with an output schema present (so return values needn't be spelled out), the description covers purpose, inputs, query syntax, and result type. The main gap is the unexplained optional `format` parameter; otherwise an agent has enough to invoke it correctly.
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 0% — parameters carry bare titles only. The description compensates substantially for `query` by illustrating path-expression syntax and for `path` by listing supported file types, but it never explains the optional `format` parameter (e.g., whether it overrides extension detection) or clarifies error behavior for `path`.
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 ('Extract values from a json/yaml/toml/csv/xml/psd1 file') plus the mechanism ('path expression') and concrete examples. It does not explicitly name or contrast sibling tools like read_file or convert_data, so the agent must infer the boundary itself.
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 examples ('servers[0].name', 'users[*].email') imply the intended use case, but there is no explicit when-to-use statement, no prerequisites, and no named alternatives for cases like raw file reading or format conversion. Usage is inferable rather than stated.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.