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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds one genuinely useful non-schema fact — a 10-credit cost and the Rider-Waite-Smith group — but says nothing about determinism of the seed, what happens with allowReversed, or the draw's behavior.

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-loads the spread identity before the metadata tags, but the brevity comes from omission rather than efficiency — the single content sentence is under-specified for a 5-parameter tool.

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 annotations cover safety. However, for a tool with five parameters, 40% schema coverage, and many near-identical siblings, the definition provides no usage routing, no spread-structure detail, and no parameter guidance — the cost line is the only added context.

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 carry no schema descriptions, and the description supplies no parameter meaning at all. The two documented params (fields, precision) are already fully explained in the schema, so the description fails to compensate for the undocumented majority.

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 the spread size and topic ("7-card relationship dynamics"), which is more than a tautology, but it omits the draw verb and does nothing to separate itself from closely related siblings such as draw_love_triangle, draw_celtic_cross, or tarot_lenormand_draw_relationship. An agent knows the domain but not the distinguishing layout.

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 mention of alternatives. With ten-plus sibling draw spreads covering career, love, decision, year-ahead, etc., the agent gets no signal about when this 7-card relationship spread is the right choice over a 3-card or 10-card spread.

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