img-src MCP Server

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It effectively describes key behavioral traits: supported formats (JPEG, PNG, etc.), size limits (max 5MB), and return values (CDN URLs). However, it doesn't mention authentication requirements, rate limits, or error conditions.

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 perfectly front-loaded with the core purpose, followed by prioritized usage guidelines, then technical details. Every sentence serves a clear purpose with zero wasted words, making it highly efficient for an AI agent to parse.

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 5-parameter upload tool with no annotations and no output schema, the description does an excellent job covering purpose, usage, formats, limits, and returns. The main gap is the lack of authentication/error information, but given the rich parameter guidance and behavioral context, it's nearly complete.

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?

With 100% schema description coverage, the baseline is 3. The description adds significant value by explaining the strategic preference hierarchy among parameters (file_path > url > data) and the practical reasoning behind it (avoiding context length limits), which goes beyond what the schema provides.

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 specific action ('Upload an image') and resource ('to img-src.io'), distinguishing it from sibling tools like delete_image, get_cdn_url, or list_images. It provides a complete picture of the tool's function beyond just the name.

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 explicit guidance on when to use each parameter ('Always prefer file_path...', 'Use url for web images', 'Only use data as last resort'), including clear alternatives and exclusions. This helps the agent select the right approach based on context.

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