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

The annotations already declare read-only, open-world, idempotent, and non-destructive behavior. The description adds useful context beyond that: the deck tradition, per-position card/orientation/meaning output, and the important behavioral note that the question is echoed verbatim and never interpreted.

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 front-loaded with the core action, lists the supported layouts compactly, and closes with a high-value behavioral caveat. There is no filler, and every sentence contributes useful information.

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?

With no output schema, the description does a good job explaining what the tool returns: per-position cards, orientation, and meanings, plus the echoed question. It is complete enough for correct invocation, though it does not describe the exact response shape or mention all schema-level behaviors such as seeded reproducibility.

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 description coverage is 100%, so the schema already documents all six parameters thoroughly. The description restates the enum layouts and custom positions, and adds the non-interpretation of `question`, but does not add detail about `seed`, `reversals`, or `session_id` beyond what the schema provides.

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 uses a specific verb and resource: it deals a named tarot spread layout from a defined deck and explains that each position gets a card, orientation, and traditional meaning. It is clear what the tool does, but it does not explicitly differentiate itself from closely named siblings such as draw_cards, get_card, random_card, or tarot_shuffle.

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?

Usage is implied through the named layouts and the custom-position option, and the schema explains seed reproduction and session_id, but the description itself does not explicitly state when to use this tool instead of alternatives like draw_cards or tarot_shuffle. The guidance is adequate but incomplete.

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