Grok MCP

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

With no annotations provided, the description carries full burden and does well by disclosing key behaviors: local images are sent as base64 data URIs with format restrictions (JPG/JPEG/PNG only) and size limits (max 20 MiB each). It also mentions session persistence and default model, though lacks details on rate limits or error handling.

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 well-structured and appropriately sized. It starts with a clear purpose statement, then details input handling, followed by a bullet-point breakdown of each parameter with meaningful explanations. Every sentence adds value with no 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?

Given 6 parameters, 0% schema coverage, no annotations, and no output schema, the description does a strong job. It covers all parameters thoroughly and explains the return value. Minor gaps include lack of error cases or output format details, but it's largely complete for the tool's complexity.

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 0%, so the description must compensate, which it does excellently. It provides detailed semantics for all 6 parameters beyond schema titles: explains 'prompt' as 'Question or instruction about the image(s)', 'session' for persistent history, 'model' as vision-capable with default, 'image_paths' and 'image_urls' as input sources, and 'detail' with enum values and default.

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 purpose: 'Analyze one or more images with a Grok vision model.' It specifies the verb ('analyze'), resource ('images'), and distinguishes from siblings by mentioning vision capabilities, unlike general chat tools like 'chat' or 'chat_with_files'.

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 usage for image analysis with Grok vision models but doesn't explicitly state when to use this tool versus alternatives like 'generate_image' or 'chat_with_files'. It mentions local vs. public URLs but lacks 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.