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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so safety is covered. The description adds the cost signal (10 credits, Tier 1), which is genuine behavioral context, but it says nothing about the return shape beyond what the output schema provides.

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?

One front-loaded sentence defines the set, followed by two short bracketed metadata lines. Nothing is padded, though the group/cost brackets are boilerplate rather than substance.

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 an output schema present and full annotation coverage, the description need only identify the dataset it returns, which it does precisely. Only the lack of routing guidance keeps it short of fully 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 description coverage is 100%, so both 'fields' and 'precision' are fully documented in the schema itself. The description adds no parameter meaning beyond that, so baseline 3 applies.

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 names a specific resource — the 40 numbered Minor Arcana cards, Ace through 10 of each suit — which is concrete and unambiguous. It implicitly distinguishes itself from the majors (22 cards) and courts siblings by scoping to 'numbered... Ace through 10', though it doesn't name those siblings explicitly.

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?

There is no guidance on when to invoke this versus the many adjacent tarot siblings (majors, courts, cards, cards_slug, keywords, suits). The agent must infer usage purely from the resource name and set definition.

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