WaveXisMCP

wavexis_eval

Evaluate a JavaScript expression in a live browser page and receive the result as JSON. Optionally navigate to a URL first, or target an existing session for page-specific testing.

Instructions

Evaluate a JavaScript expression in the browser context and return the result.

Use wavexis_scrape when the same expression must run across many pages, or wavexis_act for natural-language interaction instead of raw JS.

Side effects: launches/acquires a browser backend, navigates to url if provided, executes arbitrary JS in the page (may trigger network requests or DOM mutations). Returns: JSON string with keys: 'status' ('ok'/'error'), 'result' (Any), 'type' (str).

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "input": "<input>"
    },
    "name": "wavexis_eval"
  }
}

Input Schema

Name	Required	Description	Default
`input`	Yes

Output Schema

Name	Required	Description	Default
`result`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

Changed7 schema fields changedv1.6.24Jul 29, 2026
- addedInput schema / $defs / EvalInput / properties / backend / description
```
Added value: +"Backend: 'cdp', 'bidi', or 'auto'"
```
- addedInput schema / $defs / EvalInput / properties / backend / enum
```
Added value: +[
+  "cdp",
+  "bidi",
+  "auto"
+]
```
- addedInput schema / $defs / EvalInput / properties / headless / description
```
Added value: +"Run browser in headless mode"
```
- addedInput schema / $defs / EvalInput / properties / session_id / description
```
Added value: +"Active session ID. If omitted, a stateless session is created for this call."
```
- addedInput schema / $defs / EvalInput / properties / wait_timeout / description
```
Added value: +"Timeout in ms for wait conditions"
```
- addedInput schema / $defs / EvalInput / properties / wait_timeout / maximum
```
Added value: +300000
```
- addedInput schema / $defs / EvalInput / properties / wait_timeout / minimum
```
Added value: +1000
```
First observedv1.0.1Jul 7, 2026

TDQS

A4.4/5.0

Behavior5/5

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

Annotations only provide generic flags, so the description carries the burden of explaining side effects. It does this well: it discloses browser backend acquisition, optional navigation, and the fact that arbitrary JS may trigger network requests or DOM mutations. This goes beyond the annotations without contradicting them.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is compact and front-loaded: the first sentence states purpose, the second gives routing guidance, the third discloses side effects, and the final line documents the JSON return shape. No sentence is wasted.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given an eval tool with multiple configuration params and strong side effects, the description covers the key behavioral boundaries (browser, network, mutations), alternative tool selection, and the return contract. It stops short of describing the parameter wiring, but the nested schema contains descriptions for those fields, so the gap is acceptable. Overall it is nearly complete for a custom browser-eval tool.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters2/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage for the top-level parameter is reported as 0%, so the description should compensate for undeclared parameter semantics. It clarifies only the `url` side effect and the result format, but it does not explain `session_id`, `backend`, `headless`, `wait_timeout`, or `await_promise`. These are meaningful choices an agent must correctly interpret to invoke the tool well.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description opens with a specific verb ('Evaluate') and resource ('JavaScript expression in the browser context'), and states that it returns the result. It also names two sibling tools it is not, which differentiates it clearly from wavexis_scrape and wavexis_act.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines5/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description explicitly tells the agent when to use wavexis_scrape ('when the same expression must run across many pages') and wavexis_act ('for natural-language interaction instead of raw JS'). This gives a clear decision rule for choosing this tool versus alternatives.

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

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