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

Annotations already declare readOnlyHint=true, covering the lack of side effects. The description adds behavioral context by specifying that the tool returns an overview and that the URL is the deliverable to be presented to the user. This goes beyond the annotations and gives practical invocation guidance.

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 with no redundancy. The action and key output are front-loaded, and the deliverable instruction is concise and actionable. 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?

Given the tool's simplicity (one parameter, read-only) and lack of output schema, the description adequately covers the return content (overview of design system components) and the deliverable. It does not explicitly state the output structure (e.g., JSON object), but that is not essential for a read-only overview tool with clear component listing.

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% and the description repeats the same input concept ('standby.design URL or raw hash') without adding syntax, formatting, or edge-case details. The schema description already mentions 'from a previous generate_* call or copied from the browser,' so the description does not enhance parameter understanding.

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 specific verb ('Decode') and resource ('standby.design URL or raw hash') and enumerates the output components (color palette, type scale, spacing, shape tokens, motion springs, icons, and per-tool edit links). It clearly distinguishes from sibling generation tools by focusing on inspection rather than creation, and from get_design_rules by covering the full system overview.

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 when a standby.design URL or raw hash is available and an overview is needed, but it does not explicitly contrast with alternatives like export_design_system or get_design_rules. The deliverable instruction ('Always give the standby.design/system URL to the user') is useful but not about when to choose this tool over others.

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