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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and a closed world, so the safety profile is fully covered. The description adds genuinely new operational context not present in structured fields: the credit cost (10 credits, Tier 1) and the deck grouping, which matters for budget-aware agents. It still says nothing about how the draw behaves with a fixed seed or whether the question influences card selection.

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 bracketed lines with no filler; the purpose is front-loaded before the metadata tags. It is efficient, though bordering on under-specification rather than genuine conciseness.

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 no explanation. However, for a 5-parameter tool with 40% schema coverage, no usage guidance, and no explanation of seed/allowReversed/question semantics, the definition leaves significant gaps an agent would have to guess at.

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% across five parameters. The description explains none of them: seed, fields (compact-mode projection), question, precision, and allowReversed are left entirely to the schema, and two of them have no descriptions at all. With low coverage the description should compensate, and it does not.

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?

States a specific format and domain: '5-card career trajectory spread' under the Rider-Waite-Smith group. This distinguishes it from the Marseille career draw and from other RWS spreads like three-card or Celtic Cross. It does not name the act ('draw') explicitly, but the combination of name, title, and this line is unambiguous.

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 choose this spread over siblings such as astroway_tarot_marseille_draw_career, astroway_tarot_rider_waite_draw_three_card, or astroway_tarot_rider_waite_interpret. The 'career' qualifier implies context, but no exclusions, prerequisites, or alternatives are given.

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