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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds the deck scope and the cost/group metadata (10 credits, Tier 1), but says nothing about response size for 78 cards or any rate/credit implications beyond the single cost line.

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 tight content sentence followed by short bracketed metadata; the substance is front-loaded with no filler. Efficient, though the group/cost lines are boilerplate rather than tool-specific guidance.

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-value explanation is not required, and annotations cover the read-only safety profile. The description adequately covers content scope; the only real gap is sibling routing, which is a usage-guidelines concern rather than missing context.

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% and both parameters (fields, precision) are documented in the schema itself, so baseline 3 applies. The description adds no parameter-level detail, and notably the schema's examples (planets/houses paths) read as chart-oriented rather than tarot-oriented, a mismatch the description does not clear up.

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 ('Full 78-card RWS deck listing') and enumerates the content it carries (upright/reversed meanings, keywords, astrology, yes/no affinity), so an agent knows exactly what it retrieves. It does not, however, distinguish itself from close siblings such as astroway_tarot_rider_waite_cards_slug, _majors, _minors or _courts, which also surface card data.

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 when-to-use guidance and no mention of alternatives. With a dense sibling cluster (cards_slug, majors, minors, courts, keywords_keyword, elements_element), the agent must guess whether this full-deck listing or a filtered sibling is the right call.

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