Charlotte

charlotte_back

Navigate back in browser history to return to the previous page, then get a concise summary, content context, or full text. Use to inspect the page after backward navigation.

Instructions

Navigate back in browser history. Returns page representation after navigation.

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": "charlotte_back"
  }
}

Input Schema

Name	Required	Description	Default
`detail`	No	"minimal" (default), "summary" (includes content context), "full" (includes all text content)

Schema Changelog

Changes observed during successful MCP inspections.

Changed2 schema fields changedv0.8.0Aug 10, 2026

changedInput schema / $schema

Previous value: -"http://json-schema.org/draft-07/schema#"New value: +"https://json-schema.org/draft/2020-12/schema"

removedInput schema / additionalProperties
```
Removed value: -false
```

First observedv0.6.3May 26, 2026

TDQS

A3.8/5.0

Behavior3/5

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

With no annotations, the description carries the full burden. It discloses the main behavior (navigating back) and the return value (page representation), which provides some context. However, it omits important edge-case details such as behavior when there is no history, whether it waits for page load, and the exact nature of the 'page representation,' leaving gaps in transparency.

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 two concise sentences, front-loading the action and then adding the return type. There is no filler, redundancy, or unnecessary detail; every word earns its place.

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?

The tool is simple with one well-documented parameter and no annotations or output schema. The description covers the core purpose and return, which is largely sufficient. It could be improved by mentioning how the 'detail' parameter affects the returned representation or failure behavior with an empty history, but overall it is complete for a simple tool.

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?

The input schema provides 100% coverage for the single optional 'detail' parameter, including its enum and description. The tool description adds no additional parameter information, but the baseline of 3 applies given the high schema coverage.

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 uses a specific verb ('Navigate back') and resource ('browser history'), clearly distinguishing this from sibling tools like charlotte_forward and charlotte_navigate. It also states the return value ('page representation after navigation'), leaving no ambiguity about its function.

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

Usage Guidelines3/5

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

The description implies usage by stating the action ('navigate back'), but it does not explicitly mention when to prefer this over alternatives (e.g., charlotte_forward, charlotte_navigate) or provide exclusions. There is no guidance on scenarios like empty history, but the action itself is a clear directive.

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