alterlab-mcp-server

List Sessions

alterlab_list_sessions

Read-onlyIdempotent

List stored sessions to access domain-specific cookies for scraping login-protected pages; use the returned session_id with alterlab_scrape.

Instructions

List all stored sessions for authenticated scraping. Sessions contain cookies for specific domains, allowing you to scrape content that requires login (e.g., Amazon order history, LinkedIn profiles). Use the returned session_id with alterlab_scrape to scrape authenticated pages.

Tool call template

This tool declares no required parameters. Add optional parameters from the input schema as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {},
    "name": "alterlab_list_sessions"
  }
}

Input Schema

Name	Required	Description	Default
No arguments

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.5.0Jun 12, 2026

TDQS

A3.9/5.0

Behavior3/5

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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, so the safety profile is covered. The description usefully explains that sessions hold domain-scoped cookies and how the result is consumed, but says nothing about return shape, whether the list can be empty, pagination, or cookie sensitivity.

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?

Three short sentences: purpose first, then what a session is, then the next-step tool. No filler or repetition of the title.

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?

For a zero-parameter listing tool with no output schema, the description covers what it returns and how to use the result. It is only slightly short of complete because it does not describe the list's structure or empty-state behavior.

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

Parameters4/5

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

The tool takes no parameters, so the baseline is 4 and there is nothing for the description to compensate for.

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 ('List all stored sessions') and adds what a session is ('contain cookies for specific domains'), so the agent knows this returns stored auth state rather than e.g. crawl jobs. It does not explicitly distinguish itself from the single-session sibling alterlab_get_session, so it stops short of a 5.

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 a clear when-to-use condition ('scrape content that requires login, e.g. Amazon order history, LinkedIn profiles') and names the follow-up tool (alterlab_scrape with the returned session_id). No explicit when-not or pointer to alterlab_get_session for inspecting a single session.

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