card_builder_design_principles

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

The description discloses the topics covered (hierarchy, state feedback, spacing, etc.) and implies it is a read-only reference. However, with no annotations provided, it could more clearly state that it returns information without side effects.

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 short paragraphs: introduction, list of covered topics, and usage guidance. Every sentence adds value, no fluff. It is efficiently front-loaded with purpose.

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 parameters and having an output schema, the description explains what the tool provides comprehensively. It covers the scope and relationship to recipe_guide. It could mention read-only nature explicitly but is otherwise 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?

The tool has no parameters and 100% schema description coverage, so the baseline is 4. The description does not need to add parameter semantics.

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 that this tool is an 'Embedded UX design playbook for Card Builder cards' and distinguishes it from the sibling `recipe_guide()` tool by explaining that recipe_guide covers HOW to build a card while this covers WHAT to build for polished results. It lists specific design aspects covered.

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 says 'Read this AFTER `recipe_guide()` when you're about to design a card that needs to look polished rather than just functional.' This provides clear ordering and context for use, though it could be more explicit about when not to use it.

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