Get design context (REST lite)

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

Annotations already mark readOnlyHint and openWorldHint, but the description adds valuable behavioral context: 'REST-only' implies a different execution path than the full MCP, 'best-effort CSS flex' signals possible approximation, and 'Image fills are refs' reveals that pixel data is not included. These details go beyond what annotations provide.

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 three sentences: the first states the core purpose and contents, the second adds the disambiguation from the official tool, and the third explains image fills and alternatives. It is front-loaded with the most critical information and contains no redundant phrasing.

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 read-only snapshot tool with six well-documented parameters and no output schema, the description covers what output to expect (identity, bbox, CSS, text, fills), the nature of image fills, the optional token summary, and a caution about its unofficial status. Nothing essential for correct invocation is missing.

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%, so parameters are already well-documented. The description adds extra meaning for include_tokens, explaining it attaches a compact token summary with variables or labeled fallback and that it's optional to keep the tree small. It also gives context for the overall output, enriching the meaning of 'depth' and 'max_nodes' without repeating schema 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 states a clear verb and resource: 'REST-only codegen snapshot for a subtree' and immediately lists the content (identity, bbox, CSS flex, text, fills, component ids). It distinguishes itself from the 'official MCP get_design_context' and names alternatives for image fills, making it unmistakable among siblings.

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 warns 'Not official MCP get_design_context' and instructs to 'use get_images or bundle_image_fills for pixels,' which gives clear when-not guidance and alternatives. It doesn't explicitly compare to other get_* tools like get_nodes or get_file, but the context about REST-only and the 'lite' intent is enough to infer appropriate use.

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