Mithwire MCP

browser_storage_get

Retrieve local or session storage values from a Chromium browser session using its session ID, so agents can inspect saved data and debug web state.

Instructions

Get local/session storage values.

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": {
      "session_id": "<session_id>"
    },
    "name": "browser_storage_get"
  }
}

Input Schema

Name	Required	Description	Default
`kind`	No		both
`session_id`	Yes

Output Schema

Name	Required	Description	Default
No arguments

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.5.1Oct 18, 2026

TDQS

C2.7/5.0

Behavior2/5

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

With no annotations, the description carries the full behavioral burden and discloses almost nothing: it doesn't say whether it acts on the current tab, whether it requires an active session, how it behaves when storage is empty, or that it's a read-only operation. Only the verb "Get" weakly implies read semantics.

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?

A single short sentence with no filler and the action front-loaded. It is efficient, though the brevity tips into under-specification rather than crispness.

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

Completeness2/5

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

The output schema covers return shape and there are only two parameters, but with zero annotation coverage the description should explain the required session_id and the kind selector's semantics. For a session-scoped browser tool it leaves too much for the agent to infer.

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 is 0%, so the description must compensate and it largely doesn't. "local/session" hints at the `kind` enum but never explains the `both` default or the values `local`/`session`, and `session_id`, the only required parameter, is never mentioned at all.

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?

The description names a specific verb ("Get") and resource ("local/session storage values"), which cleanly separates it from sibling writers like browser_storage_set and browser_storage_clear. It stops short of saying anything about the browser session it operates against, but the core action is unambiguous.

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

Usage Guidelines2/5

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

There is no guidance on when to reach for this versus alternatives such as browser_evaluate, which could also read storage, or browser_cookies_get for a related but different store. No prerequisites or exclusions are given.

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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