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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is fully covered. The description adds useful non-schema context — the 10-credit Tier 1 cost and the system group — which is real value beyond the annotations. It says nothing about the meaning or structure of the soul/personality pair, so it stays at an adequate 3.

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?

Two short lines, front-loaded with the core action ('Returns soul card and personality card pair from birth date') before the metadata tags. There is no filler, though the metadata lines are housekeeping rather than substantive description.

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 needn't be explained, and the tool is a simple single-date lookup. The gaps are that the description never clarifies the distinction between the soul card and personality card concepts or routes the agent away from the near-identical birth_card sibling. Adequate but not complete for a tool sitting among many similar tarot siblings.

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%, with `fields` and `precision` documented in the schema and only `date` left to its regex pattern. The description adds no parameter meaning beyond the schema, but the required input is self-evident from the tool's stated purpose (birth date). Baseline 3 is appropriate.

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 verb and resource: it returns a soul card and personality card pair computed from a birth date. That is more precise than the title alone and an agent can tell it apart from generic draw tools. It does not, however, differentiate itself from the close sibling astroway_tarot_rider_waite_birth_card, which also derives a card from a date.

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?

The description states only what the tool returns, with no when-to-use guidance, no prerequisites, and no mention of alternative siblings (birth_card, year_card, shadow_card) that an agent might confuse it with. The '[Group: ...]' tag is categorization, not usage guidance.

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