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 covered. The description adds genuinely useful behavior context by disclosing the 10-credit cost and that the spread is 'adapted' rather than canonical, but it says nothing about how seed drives determinism or what allowReversed does.

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 definition is two short lines, front-loading the spread and style before the metadata tags. Nothing is padded, though the brevity reflects missing content rather than tight editing.

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 described, and annotations carry the safety profile. However, with 5 parameters at 40% coverage and no usage guidance, the definition is too thin for an agent to invoke it confidently versus the numerous sibling tarot draws.

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 only 40%: seed, question, and allowReversed are undocumented in the schema, and fields/precision are. The description mentions no parameters at all, so it fails to compensate for the uncovered three, leaving core inputs like the question text and reversed-card behavior unexplained.

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 identifies a specific spread (10-card Celtic Cross) and its interpretive style (Marseille pip-style), so an agent knows exactly what reading is produced. It does not differentiate from the many sibling draw tools (e.g. astroway_tarot_rider_waite_draw_celtic_cross, astroway_tarot_marseille_draw_cross, astroway_lnd_celtic_cross_lenormand), which is why it falls short of 5.

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 statement of when to choose this spread over a sibling such as draw_cross, draw_seven_card, or the Rider-Waite Celtic Cross. The name implies a draw action but the description offers no usage context or exclusions.

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