add_json_extractor

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations provided, the description must fully disclose behavioral traits. It only says 'Add', implying a mutation, but does not explain side effects like whether existing extractors are replaced, what happens if the parent sampler does not exist, or whether the operation is reversible. This is a significant gap for a mutation tool.

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 a single, tightly worded sentence that front-loads the action and purpose. Every word earns its place, with no redundant information or filler.

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 tool with no annotations and no output schema, the description is adequate but not complete. It explains the main use case, but does not mention potential behavioral details (e.g., failure handling, idempotency) or prerequisites beyond the parent sampler. The missing parameter descriptions for name and planId are not addressed. A more comprehensive description would help for a mutation operation.

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 67% (4 of 6 parameters have descriptions). The description adds no additional parameter-specific details beyond what the schema already provides; it merely restates the purpose which maps to jsonPathExpr and referenceName. Since the schema covers most parameters, the baseline of 3 is appropriate, and the description does not compensate for the undocumented name and planId parameters.

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 ('Add'), a clear resource ('JSON Extractor post-processor'), a location context ('under an HTTP sampler'), and the purpose ('save a value from the JSON response into a variable'). This clearly distinguishes it from sibling add_* tools like add_http_sampler or add_response_assertion.

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 clearly indicates when to use this tool: when you need to add a JSON extraction post-processor. It provides context about the parent sampler. However, it does not explicitly state when not to use it or mention alternatives (e.g., if you need a different extractor type), but given the sibling list, the purpose is distinct enough.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.