mcp-six-eyes
mcp-six-eyes
MCP 服务器,为纯文本 AI 代理提供理解图像的能力,包括多图像对话,如“参考图 1 和图 2”或“比较这些截图”。
纯文本模型无法看到像素。该服务器弥合了这一差距:代理调用视觉工具,服务器与多模态 API 通信,代理获得纯文本响应。
Agent (text-only)
│ tool call: analyze / compare / refer / ocr / …
▼
mcp-six-eyes (this server)
│ 1..N images: path | URL | base64 (labels: 1, 2, before, …)
▼
Vision API (OpenAI / Anthropic / Gemini / OpenRouter / custom)
│
▼
Plain-text description / OCR / comparison / structured extract
│
▼
Agent continues reasoning with text为什么有效
MCP 暴露代理可以调用的工具。代理永远不需要原生视觉能力:
用户上传或指向一张或多张图像
代理调用视觉工具,传入这些来源(以及可选的标签)
服务器加载图像并将其发送给多模态模型
服务器仅返回文本,并带有稳定的图像标签
纯文本代理像使用任何其他工具结果一样使用该文本
Related MCP server: MCP Vision Server
工具
工具 | 用途 |
| 对一张或多张图像进行通用问答 |
| 密集的场景/UI 描述(非常适合代理的“上下文转储”) |
| 提取可见文本(多图时按图像分节) |
| 对比 2 张以上图像(前后对比、A/B、变体) |
| 回答引用“图 1”、“两张图”等的问题 |
| UI/UX 截图审查和多步骤流程 |
| 图表、绘图、表格、仪表板 |
| 架构图 / 流程图 / ERD / 白板解释器 |
| 从表单、收据、表格、标签中提取结构化 JSON |
| 显示配置的提供商/模型和限制 |
图像输入
每个图像工具都接受:
单张:
image:本地路径、file://、http(s)、数据 URL 或 base64多张:
images:来源数组 或{ source, label?, mimeType? }对象可以同时传递两者;它们会被合并
标签默认为 "1"、"2"、……,因此代理提示如“比较图 1 和图 2”可以清晰映射。自定义标签也可以("before"、"after"、"fig-a")。
# one image
analyze_image({ image: "./shot.png", prompt: "What failed?" })
# multi-image with default labels 1..n
compare_images({
images: ["./a.png", "./b.png"],
prompt: "What changed in the error state?"
})
# multi-image with explicit labels (best for long threads)
refer_images({
images: [
{ source: "./login.png", label: "1" },
{ source: "./dashboard.png", label: "2" }
],
prompt: "Using image 1 and image 2, is the user authenticated?"
})支持的来源形式:
本地文件路径(
/path/to/image.png或C:\path\to\image.png)file://URIhttp(s)URL数据 URL(
data:image/png;base64,...)原始 base64(尽可能传递
mimeType)
要求
Node.js 20+
支持视觉的 API 密钥(OpenAI、Anthropic、Google、OpenRouter 或任何兼容 OpenAI 的端点)
安装
以 mcp-six-eyes 发布在 npm 上。
npx -y mcp-six-eyes或全局安装 / 作为项目依赖安装:
npm install -g mcp-six-eyes
# or
npm install mcp-six-eyes大多数人将其接入 MCP 客户端,而不是手动运行。示例 Claude Desktop / Cursor 配置:
{
"mcpServers": {
"mcp-six-eyes": {
"command": "npx",
"args": ["-y", "mcp-six-eyes"],
"env": {
"VISION_PROVIDER": "openai",
"OPENAI_API_KEY": "sk-..."
}
}
}
}为什么 npx 在这里很流行:
无需全局安装
客户端按需启动服务器
-y在首次运行时跳过安装提示npm 会缓存包以供后续启动
本地开发
npm install
npm run build然后任选其一:
{
"mcpServers": {
"mcp-six-eyes": {
"command": "npx",
"args": ["-y", "."],
"env": {
"VISION_PROVIDER": "openai",
"OPENAI_API_KEY": "sk-..."
}
}
}
}或将 Node 指向构建后的入口点:
{
"mcpServers": {
"mcp-six-eyes": {
"command": "node",
"args": ["./build/index.js"],
"env": {
"VISION_PROVIDER": "openai",
"OPENAI_API_KEY": "sk-..."
}
}
}
}环境
在 MCP 客户端的 env 块中设置提供商密钥(推荐),或在本地 .env 中设置以用于开发。
最小 OpenAI 设置:
VISION_PROVIDER=openai
OPENAI_API_KEY=sk-...可选模型 / 限制:
VISION_MODEL=gpt-4o-mini
VISION_MAX_IMAGES=10
VISION_MAX_IMAGE_BYTES=20971520
VISION_CACHE_MAX_ENTRIES=200服务器通过 stdio 使用 MCP 协议。不要将应用程序日志写入 stdout。
缓存
视觉调用按内容在内存中进行记忆化。缓存键对实际图像字节以及任务、提示、标签和令牌上限(而非来源字符串)进行哈希,因此模型对同一图像重新调用 describe_image(或任何视觉工具)时,会立即获得之前的答案,并标记为 Cached: yes,而不会再次向视觉 API 计费。
默认:
VISION_CACHE_MAX_ENTRIES=200(有界,最旧的先被淘汰)设置
VISION_CACHE_MAX_ENTRIES=0以禁用对于给定键,第一个答案生效;更改的文件或 URL 会产生新键
失败和回退响应永远不会被缓存
缓存仅在进程生命周期内有效(无磁盘持久化)
客户端说明
Claude Desktop
配置文件:
macOS:
~/Library/Application Support/Claude/claude_desktop_config.jsonWindows:
%AppData%\Claude\claude_desktop_config.json
使用 使用 npx 快速开始 中的 npx 块。
Cursor
将相同的服务器块添加到 .cursor/mcp.json(项目)或全局 Cursor MCP 配置中。
其他 stdio MCP 主机
任何能够启动的主机:
npx -y mcp-six-eyes并传递环境变量即可。
提供商
提供商 |
| 密钥环境变量 | 默认模型 |
OpenAI |
|
|
|
Anthropic |
|
|
|
Google Gemini |
|
|
|
OpenRouter |
|
|
|
自定义 OpenAI 兼容 |
|
| 设置 |
可选回退:
VISION_FALLBACK_PROVIDER=anthropic
ANTHROPIC_API_KEY=sk-ant-...示例代理用法
单张截图
User: What's wrong in this screenshot? ./screenshots/build-error.png
Agent → ocr_image({ image: "./screenshots/build-error.png" })
Agent → analyze_image({
image: "./screenshots/build-error.png",
prompt: "Explain the error and suggest a fix"
})
Agent → answers in plain text多图像:引用 / 比较
User: I uploaded two shots. Compare image 1 and 2. Did the fix work?
Agent → compare_images({
images: [
{ source: "./before.png", label: "1" },
{ source: "./after.png", label: "2" }
],
prompt: "Did the red error banner disappear after the fix?"
})User: Refer image 1 and image 2. Which CTA is primary?
Agent → refer_images({
images: [
{ source: "./landing-a.png", label: "1" },
{ source: "./landing-b.png", label: "2" }
],
prompt: "Which image has the stronger primary CTA and why?"
})UI 流程、图表、示意图、结构化提取
inspect_ui({
images: ["./step1.png", "./step2.png", "./step3.png"],
prompt: "Describe the checkout flow and any friction"
})
read_chart({
image: "https://example.com/revenue.png",
prompt: "Summarize the trend and call out outliers"
})
explain_diagram({
image: "./architecture.png",
prompt: "List services and data flow"
})
extract_from_images({
image: "./receipt.jpg",
schema: "{\"merchant\":string,\"date\":string,\"total\":number,\"items\":[{\"name\":string,\"price\":number}]}"
})架构
src/
index.ts MCP server + tools
config.ts env/provider config
image.ts path/URL/base64 loader + multi-image labels
prompts.ts task prompts (analyze/describe/ocr/compare/...)
providers/
index.ts provider router + fallback
openai-compatible.ts OpenAI / OpenRouter / custom (multi-image)
anthropic.ts Claude vision (multi-image)
google.ts Gemini vision (multi-image)
types.ts shared contracts
test/ unit tests (node:test, mocked providers)
assets/
logo.png project logo设计说明
工具而非资源:图像理解是带有副作用(API 成本)的操作,因此作为工具暴露。
纯文本输出:没有视觉能力的主机模型只需要文本内容块。
带标签的多图像:聊天 UI 中的代理谈论“图 1/2”;标签保持这种基础稳定。
任务特定工具:compare / refer / UI / chart / diagram / extract 在工具选择上优于一个巨型提示。
Stdio 传输:桌面代理最简单的本地集成。
无 stdout 日志:stdout 保留给 JSON-RPC;诊断信息发送到 stderr。
提供商抽象:无需更改代理学习的工具名称即可切换后端。
开发
npm install
npm test
npm start脚本 | 用途 |
| 将 TypeScript 编译到 |
| 仅类型检查 |
| 构建 + 完整单元测试套件 |
| 针对当前 |
| 快速图像加载器冒烟脚本 |
| 在 stdio 上运行 MCP 服务器 |
使用 MCP Inspector 调试:
npx @modelcontextprotocol/inspector node ./build/index.js有关 PR 和编码指南,请参阅 CONTRIBUTING.md。
链接
npm: mcp-six-eyes
维护者: rimunace
发布工作流
本地更改后的维护者路径:
# one-time
npm login
# bump version + CHANGELOG, then ship
npm test
npm publish --access public可选辅助脚本(测试,然后 npm publish):
npm run release安全
API 密钥保留在环境变量 / 客户端配置中,绝不会出现在工具响应中
远程 URL 获取是明确的工具输入;请谨慎对待不受信任的 URL
通过
VISION_MAX_IMAGE_BYTES拒绝大图像(默认 20MB)每次调用的图像数量通过
VISION_MAX_IMAGES限制(默认 10)响应缓存仅将内容哈希和结果文本保存在内存中;不会持久化到磁盘
完整政策:SECURITY.md。
贡献
欢迎提交 issue 和 pull request。请在打开 PR 之前运行 npm test,并阅读 CONTRIBUTING.md。
许可证
Available Tools
10 toolsanalyze_imageA
Analyze one or more images with a vision model and return plain text. Use for general Q&A when the host model cannot see images. Supports single image or multi images (image 1, image 2, ...).
| Name | Required | Description | Default |
|---|---|---|---|
| image | No | Local file path, file:// URI, http(s) URL, data URL, or base64 image data | |
| images | No | One or more images. Prefer this for multi-image chats: ["path/a.png", "path/b.png"] or [{source, label: "1"}, {source, label: "2"}]. Labels default to "1", "2", ... | |
| prompt | No | What to analyze or answer (errors, UI review, chart meaning, differences, etc.) | |
| mimeType | No | Optional MIME type hint for a single bare-base64 `image` input, e.g. image/png |
TDQS
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
There are no annotations, so the description bears the transparency burden. It discloses the vision-model dependency and that output is plain text. However, it does not mention potential limitations, error behavior, or whether any authentication or prerequisites apply, leaving some behavioral uncertainty.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
Three short, front-loaded sentences with no filler. It states purpose, use case, and supported modes efficiently. Every sentence earns its place.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a simple general-purpose vision tool, the description is mostly complete: it names the model limitation, output type, and single/multi-image support. However, it does not explicitly differentiate from specialized siblings or clarify whether a prompt is expected if not provided, leaving minor gaps.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 100%, so the baseline is 3. The description adds a small clarification that single vs. multi images are supported via 'image' or 'images', but this mostly repeats what the schema already explains. It does not add meaningful new semantics beyond the schema.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states a specific verb and resource: 'Analyze one or more images with a vision model and return plain text.' It also distinguishes itself from sibling tools by framing itself as 'general Q&A when the host model cannot see images,' setting it apart from specialized tools like ocr_image or compare_images.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
It explicitly says when to use: 'Use for general Q&A when the host model cannot see images.' This gives clear for-use context, but it does not explicitly mention when not to use specialized alternatives (e.g., describe_image, ocr_image), so it earns a 4 rather than a 5.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
compare_imagesA
Compare two or more images and explain similarities/differences. Use for "compare image 1 and 2", before/after, A/B UI, design variants, or sequential screenshots.
| Name | Required | Description | Default |
|---|---|---|---|
| image | No | Local file path, file:// URI, http(s) URL, data URL, or base64 image data | |
| images | Yes | One or more images. Prefer this for multi-image chats: ["path/a.png", "path/b.png"] or [{source, label: "1"}, {source, label: "2"}]. Labels default to "1", "2", ... | |
| prompt | No | What to compare or how to weigh differences (e.g. "focus on the error banner") | |
| mimeType | No | Optional MIME type hint for a single bare-base64 `image` input, e.g. image/png |
TDQS
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden. It correctly conveys a read-only comparison behavior, but does not disclose output format, handling of remote images (only in schema), or any limitations. It is adequate but not rich in behavioral context.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is concise, with just two sentences. It front-loads the core purpose and then lists concrete use cases. There is no redundancy or filler, making it highly scannable for an agent.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
The description clearly explains what the tool does and when to use it, but with no output schema or annotations, it lacks details about the response format, error handling, or constraints like maximum image count. It is sufficient for a straightforward tool but leaves some context to be inferred.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
The input schema already provides detailed descriptions for all parameters, including examples for the 'images' array. The description reinforces the comparison purpose but does not add new parameter-level semantics beyond what the schema already states, so the baseline of 3 is appropriate.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the tool's core function: 'Compare two or more images and explain similarities/differences.' It uses a specific verb and resource, and the examples (before/after, A/B UI, design variants) make it easy to distinguish from sibling tools like analyze_image or describe_image.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The 'Use for' clause gives explicit scenarios (comparing image 1 and 2, before/after, A/B UI), providing strong guidance on when to invoke this tool. However, it does not explicitly mention alternatives or when not to use it, though the sibling tool list offers context for exclusion.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
describe_imageA
Produce a detailed textual description of one or more images so a text-only model can reason about them. Prefer for general scene/UI understanding and multi-upload context dumps.
| Name | Required | Description | Default |
|---|---|---|---|
| image | No | Local file path, file:// URI, http(s) URL, data URL, or base64 image data | |
| images | No | One or more images. Prefer this for multi-image chats: ["path/a.png", "path/b.png"] or [{source, label: "1"}, {source, label: "2"}]. Labels default to "1", "2", ... | |
| prompt | No | Optional extra instruction for the vision model | |
| mimeType | No | Optional MIME type hint for a single bare-base64 `image` input, e.g. image/png |
TDQS
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the burden of behavioral disclosure. It states the output is a textual description for text-only models, implying a read-only, non-destructive operation. It also adds context about handling multiple images, but omits details like output length or potential limitations, which keeps it from a 5.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is just two sentences, with the primary action front-loaded and a concise usage hint in the second sentence. It contains no redundant information and earns its place entirely.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
The tool has a comprehensive input schema and a description that covers its main purpose and appropriate use cases. Since there is no output schema, the mention of 'detailed textual description' adequately communicates the return type. The description is sufficient for the tool's complexity, though it could have added examples or error behavior.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
The schema already provides 100% coverage of parameter descriptions, setting a baseline of 3. The description enriches this by noting the 'multi-upload context dumps' use case, which clarifies the intended usage of the 'images' parameter and adds value beyond the schema.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the tool's function: producing a detailed textual description of images. The phrase 'general scene/UI understanding and multi-upload context dumps' distinguishes it from specialized siblings like ocr_image or read_chart, making the purpose specific and differentiated.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description explicitly states when to use the tool ('Prefer for general scene/UI understanding and multi-upload context dumps'), providing clear context for selection. However, it does not name specific alternative tools or exclusion conditions, so it stops short of full when/when-not guidance.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
explain_diagramA
Explain architecture diagrams, flowcharts, sequence diagrams, ERDs, UML, whiteboards, and similar figures for a text-only agent.
| Name | Required | Description | Default |
|---|---|---|---|
| image | No | Local file path, file:// URI, http(s) URL, data URL, or base64 image data | |
| images | No | One or more images. Prefer this for multi-image chats: ["path/a.png", "path/b.png"] or [{source, label: "1"}, {source, label: "2"}]. Labels default to "1", "2", ... | |
| prompt | No | Optional extra instruction for the vision model | |
| mimeType | No | Optional MIME type hint for a single bare-base64 `image` input, e.g. image/png |
TDQS
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries full burden for behavioral disclosure. It only says 'Explain ... for a text-only agent'; it does not mention multi-image handling, label semantics, whether the explanation is a textual narrative, or any limitations.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
Single sentence, front-loaded with the verb and subject, and every word earns its place. No redundancy or filler.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
With no output schema and no annotations, the description is minimal but adequate for a moderately complex vision tool. It misses details about return format and multi-image behavior, which are important given the 'images' parameter.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema coverage is 100%, with detailed descriptions for image, images, prompt, and mimeType, so the baseline is 3. The tool description adds no additional parameter semantics beyond the general diagram context.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description uses a specific verb ('Explain') and enumerates concrete resource types (architecture diagrams, flowcharts, sequence diagrams, ERDs, UML, whiteboards), clearly distinguishing it from sibling tools like describe_image or read_chart. The phrase 'for a text-only agent' adds audience specificity.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description implies appropriate use by listing diagram categories and noting the tool is for a text-only agent, but it does not explicitly state when to prefer this over siblings or when not to use it. Still, the context is reasonably clear.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
extract_from_imagesA
Extract structured data (JSON) from one or more images: forms, receipts, IDs, tables, invoices, labels. Optional schema steers field names.
| Name | Required | Description | Default |
|---|---|---|---|
| image | No | Local file path, file:// URI, http(s) URL, data URL, or base64 image data | |
| images | No | One or more images. Prefer this for multi-image chats: ["path/a.png", "path/b.png"] or [{source, label: "1"}, {source, label: "2"}]. Labels default to "1", "2", ... | |
| prompt | No | Extra extraction instructions (locale, currency, etc.) | |
| schema | No | Optional JSON schema or field list for structured extraction, e.g. {"title":string,"total":number} | |
| mimeType | No | Optional MIME type hint for a single bare-base64 `image` input, e.g. image/png |
TDQS
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the burden of behavioral disclosure. It does disclose a meaningful behavioral trait: 'Optional schema steers field names', indicating how the schema parameter affects output. However, it does not mention whether the tool is read-only, how images are handled, or any limitations or side effects, 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.
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is a single, concise sentence that immediately states the tool's core function and adds relevant examples. There is no wasted wording, and every clause contributes to understanding the tool's purpose and key behavior (schema steering).
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the tool has 5 parameters, no output schema, and no annotations, the description provides enough context for an agent to understand the primary use case and output type (JSON). The rich schema descriptions fill in parameter details, but the description could more explicitly describe the shape of the return value (e.g., object vs array) and any edge cases. Overall, it is adequately complete but not exhaustive.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
The input schema provides 100% description coverage for all parameters, so the baseline is 3. The description adds a small amount of context by explaining that schema influences field names, but this is already implied in the schema's own description. No additional parameter-level meaning is provided beyond what the schema already covers.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description uses a specific verb ('Extract') and resource ('images'), and clearly states the output is 'structured data (JSON)'. The enumeration of document types (forms, receipts, IDs, tables, invoices, labels) distinguishes it from sibling tools like describe_image or ocr_image, making the tool's unique purpose unambiguous.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description provides clear context for when to use the tool by listing concrete document types (forms, receipts, IDs, tables, invoices, labels). However, it does not explicitly mention when not to use it or name alternative tools for different tasks, such as ocr_image or describe_image, so it stops short of full exclusion guidance.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
inspect_uiA
Inspect UI screenshots: layout, components, states, copy, errors, and likely UX/accessibility issues. Accepts one screen or a multi-step flow.
| Name | Required | Description | Default |
|---|---|---|---|
| image | No | Local file path, file:// URI, http(s) URL, data URL, or base64 image data | |
| images | No | One or more images. Prefer this for multi-image chats: ["path/a.png", "path/b.png"] or [{source, label: "1"}, {source, label: "2"}]. Labels default to "1", "2", ... | |
| prompt | No | Optional extra instruction for the vision model | |
| mimeType | No | Optional MIME type hint for a single bare-base64 `image` input, e.g. image/png |
TDQS
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden. It discloses that the tool inspects UI screenshots for specific categories and can handle multiple images, but does not describe output format, limitations, or side effects (though read-only by nature).
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is two sentences, front-loaded with the core purpose, and every word adds value. No filler.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
The tool is relatively simple, and the description covers the input modes (single or multi-image) and the scope of analysis. However, with no output schema, it would benefit from stating what the tool returns, though the inspection context implies a textual report.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema coverage is 100% with descriptions for image, images, prompt, and mimeType. The description's phrase 'multi-step flow' adds a small nuance to the images parameter, but overall it does not exceed the schema's detail.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description uses the specific verb 'Inspect' with resource 'UI screenshots' and lists concrete aspects (layout, components, states, copy, errors, UX/accessibility). This clearly distinguishes it from siblings like analyze_image or describe_image, which are more generic image analysis tools.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description states it accepts 'one screen or a multi-step flow', giving clear input context. It doesn't explicitly mention alternatives or when-not-to-use, but the UI focus implicitly guides selection over generic image tools.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
ocr_imageA
Extract readable text from one or more images (screenshots, documents, diagrams, error dialogs). Multi-image calls return a section per image label.
| Name | Required | Description | Default |
|---|---|---|---|
| image | No | Local file path, file:// URI, http(s) URL, data URL, or base64 image data | |
| images | No | One or more images. Prefer this for multi-image chats: ["path/a.png", "path/b.png"] or [{source, label: "1"}, {source, label: "2"}]. Labels default to "1", "2", ... | |
| prompt | No | Optional extra instruction for the vision model | |
| mimeType | No | Optional MIME type hint for a single bare-base64 `image` input, e.g. image/png |
TDQS
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the burden. It does disclose that multi-image calls 'return a section per image label', which is a useful behavioral trait. However, it omits potential limitations (e.g., language support, handwritten text, supported formats) or side effects, leaving a moderate transparency level.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is extremely concise: two sentences. The first sentence states the primary purpose, and the second adds the key multi-image behavior. Every word earns its place with no filler or redundancy.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a 4-parameter tool with a rich schema and no output schema, the description covers the core purpose and important multi-image output behavior. It could have added explicit differentiation from the similar-sounding 'extract_from_images' sibling, but the overall context is sufficient for selecting this tool.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 100%, and every parameter already has detailed meanings in the schema. The description's mention of 'a section per image label' adds context to the images array's label property, but that is minor. It doesn't further explain parameters beyond the schema, so the baseline of 3 holds.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description opens with 'Extract readable text from one or more images' – a specific verb and resource that clearly defines OCR functionality. Examples (screenshots, documents, diagrams, error dialogs) further clarify the intended use. The multi-image note distinguishes it from single-image analysis tools like describe_image or analyze_image.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description clearly implies when to use: whenever readable text needs to be extracted from images, with multiple image example types. The multi-image behavior is stated, but there is no explicit exclusions or naming of alternative tools (e.g., extract_from_images) for when not to use this tool.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
read_chartA
Read charts, graphs, plots, tables, and dashboards. Extracts axes, series, trends, and key values (marks estimates when exact pixels are unclear).
| Name | Required | Description | Default |
|---|---|---|---|
| image | No | Local file path, file:// URI, http(s) URL, data URL, or base64 image data | |
| images | No | One or more images. Prefer this for multi-image chats: ["path/a.png", "path/b.png"] or [{source, label: "1"}, {source, label: "2"}]. Labels default to "1", "2", ... | |
| prompt | No | Optional extra instruction for the vision model | |
| mimeType | No | Optional MIME type hint for a single bare-base64 `image` input, e.g. image/png |
TDQS
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the full burden. It discloses a key behavioral trait: 'marks estimates when exact pixels are unclear', which adds transparency about output reliability. It also implies a read-only, non-destructive operation, though it could further explain output format or limitations.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is two short sentences, front-loaded with the tool's core purpose and immediately followed by extraction details. Every clause provides value—no filler or repetition of the tool name.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Without an output schema, the description helps by listing what is extracted (axes, series, trends, key values) and the estimate behavior. The parameter schema covers multi-image usage, so the description doesn't need to repeat that. It's sufficient for a read-only chart tool, though it could be more explicit about return structure.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 100%, so the baseline is 3. The description does not add any parameter-specific details beyond what the schema already documents. It doesn't explain the difference between 'image' and 'images' or how the 'prompt' parameter modifies behavior, but the schema itself is thorough.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description uses a specific verb ('Read') and resource ('charts, graphs, plots, tables, and dashboards'), and enumerates what it extracts ('axes, series, trends, and key values'). This clearly distinguishes it from sibling tools like ocr_image or describe_image, which handle different tasks.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description provides clear context for when to use the tool (any chart-like visual input) but does not explicitly mention alternatives or when not to use it. The context is specific enough for an agent to decide, but it stops short of naming sibling tools or exclusions.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
refer_imagesA
Answer a question that refers to specific uploads by label ("refer image 1 and 2", "only the second screenshot", "both figures"). Grounds every claim in image labels.
| Name | Required | Description | Default |
|---|---|---|---|
| image | No | Local file path, file:// URI, http(s) URL, data URL, or base64 image data | |
| images | Yes | One or more images. Prefer this for multi-image chats: ["path/a.png", "path/b.png"] or [{source, label: "1"}, {source, label: "2"}]. Labels default to "1", "2", ... | |
| prompt | Yes | User question with image references, e.g. "Using image 1 and image 2, which button is primary?" | |
| mimeType | No | Optional MIME type hint for a single bare-base64 `image` input, e.g. image/png |
TDQS
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden. It discloses a meaningful behavioral trait ('Grounds every claim in image labels') but does not mention output format, error handling, or potential side effects. This is a minimal but non-empty disclosure.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is two sentences, front-loaded with the core purpose, and uses illustrative examples without fluff. Every word earns its place, and the structure is clear and readable.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a Q&A tool with no output schema, the description adequately conveys the core use case, differentiates from many siblings, and aligns with the schema's parameter intent. It lacks explicit return-value specifications, but the schema and examples cover the main selection and invocation needs.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 100%, which sets a baseline of 3. The description adds examples of label usage and prompt wording, reinforcing the schema's label semantics, but does not introduce meaning beyond what the schema already details.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description uses a specific verb ('Answer') and a clear resource ('question that refers to specific uploads by label'). It provides concrete examples ('refer image 1 and 2', 'only the second screenshot') and distinguishes from sibling tools by focusing on multi-image labeled references and grounding claims in labels.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description gives clear context for when to use the tool through examples of referring to specific uploads by label. However, it does not explicitly mention when not to use it or name alternative sibling tools, so it stops short of full guidance.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
vision_statusA
Show which vision provider/model this MCP server is configured to use, plus image limits.
| Name | Required | Description | Default |
|---|---|---|---|
No parameters | |||
TDQS
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the burden. It clearly indicates a read-only operation ('Show') with a well-defined scope (server configuration). However, it does not mention output format, potential errors, or whether any network calls are made, which are minor omissions for such a simple status tool.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is a single, well-structured sentence that immediately states the main purpose. It includes all necessary information without redundancy or filler.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a no-input, read-only status tool, the description is complete. It states exactly what the tool shows (provider/model and image limits), which is sufficient since there is no output schema to explain and no parameters to document.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
The tool has zero parameters, and the schema is empty. The description adds no parameter-specific meaning because none are needed. With zero parameters, a baseline of 4 applies, and there is no gap to compensate for.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description uses a specific verb ('Show') and clearly identifies the resource: the configured vision provider/model plus image limits. It distinguishes itself from the sibling image-analysis tools, which are all about processing images rather than reporting server configuration.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The tool's role as a status/config query is implied by the description, but there is no explicit guidance on when to use it versus the image-analysis siblings. No alternatives or exclusions are mentioned, only a clear contextual inference from the tool name and siblings.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Tool Schema Changelog
Recent tool additions, removals, and schema changes observed during successful MCP inspections.
10 tool updates
v1.1.0- First observed
analyze_image - First observed
compare_images - First observed
describe_image - First observed
explain_diagram - First observed
extract_from_images - First observed
inspect_ui - First observed
ocr_image - First observed
read_chart - First observed
refer_images - First observed
vision_status
TDQS
Scored across 10 tools
Most tools have clearly distinct purposes: general Q&A, description, OCR, comparison, UI inspection, chart reading, diagram explanation, and structured extraction. Some overlap exists between analyze_image, describe_image, and refer_images, but their descriptions clarify the intended use cases, so agent confusion is unlikely.
The naming convention is largely verb_noun (analyze_image, compare_images, inspect_ui, read_chart, explain_diagram, extract_from_images). Minor deviations include vision_status (noun_noun) and ocr_image (acronym as verb), but the pattern is readable and predictable overall.
With 10 tools, the server is well-scoped for an image analysis domain. Each tool addresses a distinct need, and the count is within the ideal 3-15 range for a focused MCP server.
The tool surface covers general image Q&A, detailed description, OCR, comparison, labeled references, UI inspection, chart reading, diagram explanation, and structured data extraction—no obvious dead ends or missing essential operations for an image understanding server.
Maintenance
Related MCP Connectors
OCR, transcription, file extraction, and image generation for AI agents via MCP.
MCP server for Qwen Image 3 AI image generation
MCP server for building and testing AI agents with multi-model experimentation and insights.
MCP server for OpenAI API (chat completions, image generation, embeddings) via AceDataCloud
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