jevpilot

browser_run

Opens a new browser session, drives Chrome toward a stated goal, and returns a session ID plus a verified result or concrete question to continue.

Instructions

Open a new browser session and work toward a goal. Jev acts fast on its own and hands back early with a question when unsure; continue with browser_act / browser_resume from the returned snapshot. Returns a session ID and a status; handoff statuses include a concrete question for the agent or user. Reuse the session with browser_resume, browser_observe, browser_act, and browser_close.

Input Schema

TableJSON Schema

Name	Required	Description
`url`	No	Initial HTTP(S) URL. Omit to start on a blank tab.
`goal`	Yes	Task to complete in the browser.
`budget`	No	Per-invocation limits.
`values`	No	Every piece of text the page needs typed (search terms, form fields) must be given here as { short field description: text }. Text inside the goal is never typed. Secrets use {secret_ref: 'env:NAME' or 'file:PATH', origins: [...] }.
`profile`	No	Configured engine profile name; defaults to the server engine.
`success`	No	Optional checks that are false now and become true only when the goal is done, e.g. url_matches for the result page. Checks that already hold on the start page are ignored.
`thresholds`	No	Per-session decision confidence thresholds (0 to 1).
`constraints`	No	Navigation allowlist and irreversible-action gate.
`navigation_timeout_ms`	No	Navigation timeout in milliseconds; defaults to 30000.

Output Schema

TableJSON Schema

Name	Required	Description	Default
`url`	Yes
`title`	Yes
`trace`	Yes
`usage`	Yes
`reason`	Yes
`status`	Yes
`timing`	Yes
`details`	No
`session`	Yes
`question`	Yes
`snapshot`	Yes
`screenshot_path`	No

Schema Changelog

Changes observed during successful MCP inspections.

Changed1 schema field changedv0.2.0Oct 1, 2026

changedOutput schema / properties / trace / items / properties / outcome / enum

Previous value: -[
-  "changed",
-  "unchanged",
-  "stale",
-  "covered",
-  "disabled",
-  "invisible",
-  "not-editable",
-  "unstable",
-  "select-failed",
-  "dialog-opened",
-  "value-not-set",
-  "accepted",
-  "dismissed"
-]New value: +[
+  "changed",
+  "unchanged",
+  "stale",
+  "covered",
+  "disabled",
+  "invisible",
+  "not-editable",
+  "unstable",
+  "select-failed",
+  "dialog-opened",
+  "value-not-set",
+  "not-focusable",
+  "accepted",
+  "dismissed"
+]

First observedv0.1.0Sep 29, 2026

TDQS

A3.8/5.0

Behavior4/5

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

With no annotations, the description carries full burden and does disclose the key operating model: Jev 'acts fast on its own and hands back early with a question when unsure,' and returns a session ID plus a status whose handoff statuses include a concrete question. That autonomy/handoff behavior is not derivable from the schema. It omits safety-relevant traits such as the irreversible-action gate and credential/secret handling, so it is not fully transparent.

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

Conciseness4/5

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

Four tight sentences, front-loaded with the action, then continuation, then return values. Every sentence carries signal; only the closing reuse list is mildly redundant with the continuation sentence.

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

Completeness3/5

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

For a 9-parameter agentic tool with nested objects and no annotations, the description covers starting, continuing, and return shape (with an output schema covering return details). It does not explain the budget semantics, the irreversible-action gate, or default constraint behavior, leaving meaningful gaps for a tool this complex.

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

Parameters3/5

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 all 9 parameters (url, goal, budget, values, success, constraints, etc.). The description adds no parameter-level meaning beyond the schema, which is the baseline case.

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

Purpose4/5

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

States a specific verb and resource: 'Open a new browser session and work toward a goal.' An agent can immediately tell this starts a session rather than continuing one. It does not contrast against browser_navigate or jev_decide, but the continuations it names (browser_act/browser_resume) make the distinction from those siblings clear.

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

Usage Guidelines4/5

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

Gives clear routing: use this to start, then continue with browser_act/browser_resume from the returned snapshot, and lists browser_resume/browser_observe/browser_act/browser_close as reuse paths. No explicit when-not or prerequisite conditions (e.g. when to prefer jev_decide or browser_navigate), so it stops just short of a 5.

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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