Draw.io 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 states the tool retrieves a selected cell and returns JSON attributes, but lacks details on permissions, error handling (e.g., if no cell is selected), or response format specifics. This is a significant gap for a tool with no annotation coverage.

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, efficient sentence that front-loads the core action ('retrieve selected cell') and includes key details like resource scope and response format. It avoids waste, though it could be slightly more structured by separating usage context.

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 no annotations, no output schema, and low complexity (0 parameters), the description is minimally adequate. It covers the basic purpose and response type but lacks behavioral context (e.g., error cases) and usage guidelines, leaving clear gaps for an agent to invoke it correctly.

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 has 0 parameters with 100% coverage, so no parameter documentation is needed. The description correctly does not add parameter information, maintaining focus on the tool's purpose. A baseline of 4 is appropriate as it avoids unnecessary 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 clearly states the verb 'retrieve' and the resource 'selected cell (whether vertex or edge) on the current page of a Draw.io diagram', making the purpose specific and understandable. However, it does not explicitly differentiate from sibling tools like 'get-shape-by-name' or 'get-shapes-in-category', which also retrieve diagram elements, so it misses the highest score.

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 no guidance on when to use this tool versus alternatives. It does not mention prerequisites (e.g., needing a diagram open), exclusions, or compare to siblings like 'get-shape-by-name' for non-selected cells, leaving usage context implied at best.

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