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es3154

Turf-MCP

by es3154

transformation_lineOffset

Calculate offset lines from GeoJSON LineString or MultiLineString features by a specified distance in various units for geospatial analysis.

Instructions

计算线的偏移。

该函数使用 Turf.js 库的 lineOffset 方法,计算给定线的偏移线。

Args: line: GeoJSON LineString 或 MultiLineString 特征或几何图形 - 类型: str (JSON 字符串格式的 GeoJSON) - 格式: 必须符合 GeoJSON LineString 或 MultiLineString 规范 - 坐标系: WGS84 (经度在前,纬度在后) - 示例: '{"type": "LineString", "coordinates": [[-74, 40], [-78, 42], [-82, 35]]}'

distance: 偏移距离
    - 类型: float
    - 描述: 线的偏移距离,可以为负值
    - 示例: 10.0

options: 可选参数配置
    - 类型: str (JSON 字符串) 或 None
    - 可选字段:
        - units: 距离单位 (默认: 'kilometers')
            - 有效值: 'miles', 'nauticalmiles', 'kilometers', 'meters', 'yards', 'feet', 'inches'
    - 示例: '{"units": "miles"}'

Returns: str: JSON 字符串格式的偏移线 GeoJSON Feature - 类型: GeoJSON Feature with LineString or MultiLineString geometry - 格式: {"type": "Feature", "geometry": {"type": "LineString", "coordinates": [...]}} - 示例: '{"type": "Feature", "geometry": {"type": "LineString", "coordinates": [[-74.1, 40.1], [-78.1, 42.1], [-82.1, 35.1]]}}'

Raises: Exception: 当 JavaScript 执行失败、超时或输入数据格式错误时抛出异常

Example: >>> import asyncio >>> line = '{"type": "LineString", "coordinates": [[-74, 40], [-78, 42], [-82, 35]]}' >>> options = '{"units": "miles"}' >>> result = asyncio.run(lineOffset(line, 10.0, options)) >>> print(result) '{"type": "Feature", "geometry": {"type": "LineString", "coordinates": [[-74.1, 40.1], [-78.1, 42.1], [-82.1, 35.1]]}}'

Notes: - 输入参数 line 和 options 必须是有效的 JSON 字符串 - 坐标顺序为 [经度, 纬度] (WGS84 坐标系) - 距离可以为负值,表示相反方向的偏移 - 依赖于 Turf.js 库和 Node.js 环境

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
lineYes
distanceYes
optionsNo

Output Schema

TableJSON Schema
NameRequiredDescriptionDefault
resultYes
Behavior4/5

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

With no annotations provided, the description carries the full burden. It effectively discloses behavioral traits: it specifies the underlying library (Turf.js lineOffset), dependencies (Node.js environment), error conditions (raises Exception on failure, timeout, or bad input), and operational details (negative distance for opposite direction, coordinate system WGS84). This covers key aspects like implementation, constraints, and failure modes, though it could mention performance or rate limits.

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?

The description is well-structured with clear sections (Args, Returns, Raises, Example, Notes) and front-loaded purpose. It is appropriately sized for a tool with 3 parameters and complex behavior. Some redundancy exists (e.g., repeating JSON string info), but overall it is efficient and easy to navigate.

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

Completeness5/5

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

Given the tool's complexity (geometric operation with 3 parameters, no annotations, but has output schema), the description is highly complete. It covers purpose, parameters, return values (though output schema exists, it still explains format), errors, examples, and notes on dependencies and constraints. This provides all necessary context for an agent to use the tool correctly.

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

Parameters5/5

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 fully. It does so excellently: for each of the 3 parameters, it provides detailed semantics including types, formats, examples, valid values (for options.units), and constraints (e.g., line must be valid GeoJSON, distance can be negative). This adds substantial meaning beyond the bare schema, making parameters well-understood.

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 starts with '计算线的偏移' (calculates line offset), which is a specific verb+resource statement. It clearly distinguishes this tool from siblings like 'transformation_buffer' (which creates buffers) or 'transformation_transformTranslate' (which translates geometries) by focusing on offsetting lines specifically. The purpose is immediately apparent and differentiated.

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 through the example and notes (e.g., for offsetting lines with Turf.js), but does not explicitly state when to use this tool versus alternatives like 'transformation_buffer' or other geometric transformations. It provides technical context (e.g., coordinate order, JSON format) but lacks explicit guidance on tool selection among siblings.

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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