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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered. The description adds billing context (10 credits, Tier 1), which the agent cannot get from annotations. It says nothing about randomization, seeding, or what the layout output looks like, but with annotations and an output schema present, a 3 is appropriate.

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?

Front-loaded single line of substance, with group and cost tags on separate lines. Nothing is padded, though the tag lines occupy real estate for little semantic value beyond cost.

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?

An output schema exists, so return format is not the description's burden, and the title plus card count make the spread self-explanatory. Still, with 5 parameters at low coverage and no usage or draw-mechanics context, the definition is only minimally 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?

Schema coverage is only 40% across 5 parameters, and the description adds no parameter meaning at all. It does not explain seed, fields, precision, or allowReversed; 'every card and house used' only loosely hints that reversals may apply. The description fails to compensate for the low coverage.

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?

States a specific action and scope: 'Full 36-card layout: every card and house used.' This distinguishes it from the smaller spreads among siblings (three_card, line_of_five, 9_card_square) by naming the full-deck scope. It never explicitly frames itself as a spread variant versus those siblings, though the card count does the differentiating work.

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?

No when-to-use guidance and no alternatives named. The agent is left to infer that this is the heaviest Lenormand spread versus draw_three_card or draw_9_card_square, and there is no hint about prerequisites or when a smaller spread would be preferable.

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