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

The annotations already declare this a safe, idempotent, closed-world read, so the safety burden is lifted. The description adds genuinely useful non-schema context: it is a 10-credit Tier 1 operation in the Tarot: Marseille group. It says nothing about how reversed cards behave, how the seed affects reproducibility, or what a draw returns.

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?

Very lean and front-loaded: the purpose sentence leads, metadata follows. Nothing is padded, though the brevity comes at the cost of the guidance and parameter detail noted elsewhere.

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, and cost/group metadata is present. But with 5 parameters, 0 required, 40% schema coverage, and undocumented `question`/`allowReversed`/`seed`, the description leaves an agent guessing about the core invocation inputs for a divination draw.

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%: `fields` and `precision` are documented in the schema, but `seed`, `question`, and `allowReversed` are bare. The description supplies no parameter meaning at all, so it fails to compensate for the coverage gap on a 5-parameter tool.

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 verb (draw) and resource (single card) qualified by deck (Marseille), which does distinguish it from siblings like draw_three_card, draw_celtic_cross, and the Rider-Waite single draw. It stops short of explicitly framing the contrast, relying on the name and deck qualifier to do the differentiation work.

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 conditions or prerequisites, and no mention of the sibling spreads (three-card, Celtic Cross, love, career) or the equivalent Rider-Waite single draw. Usage is only implied by the tool name.

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