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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered structurally. The description's one added behavioral fact is the cost ('10 credits, Tier 1'), which is genuinely useful and not present in annotations, but nothing is said about the nature of the result or any auth/limits.

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?

It is short and front-loaded, but the leading sentence is vague and half the content is bracketed metadata tags rather than operative information. It is concise without being informative, which is under-specification rather than true economy.

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 values need not be explained, but the description still leaves the core concept ('cross-sum') and the meaning of the required date input undefined. For a parameterized tool with a required input, this is too thin for an agent to invoke it correctly.

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 67%: 'fields' and 'precision' are documented in-schema, but the required 'date' parameter carries only a regex pattern with no explanation of whether it is a birth date or a query date. The description mentions no parameters at all and so fails to compensate for the undocumented required field.

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 reads 'Birth-card meditation pair for court-card practice,' which gestures at the theme but never states the operation (computing a cross-sum between a birth card and a court card) or what the tool returns. It does not distinguish this tool from close siblings like astroway_tarot_rider_waite_birth_card or astroway_tarot_rider_waite_courts, so an agent cannot confidently separate them.

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, no prerequisites, and no named alternatives among the many Rider-Waite-Smith tarot siblings. The only contextual line is a cost/group tag, which does not help an agent decide whether this tool or a 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.