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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and closed-world, so the safety profile is fully covered without the text. The description usefully adds operational facts the annotations do not carry: the endpoint, that it is a POST, and a cost of 10 credits (Tier 1). It says nothing about return shape or whether the draw is deterministic given the seed.

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 three short lines and the one substantive statement, 'Single advice card', is front-loaded ahead of the metadata brackets. Nothing is padded or repetitive; it is terse but well organized.

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?

With six optional parameters, no required fields, and a specialized domain (RWS tarot), the description does far too little: it omits usage routing, omits any explanation of the undocumented parameters, and only gestures at cost. The output schema covers return values, so that omission is fine, but the input-side gaps are substantial.

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 coverage is only 50%: art, fields, and precision are documented in the schema, but seed, question, and allowReversed (which defaults to true) have no descriptions anywhere. The description does not compensate for that gap in any way, and 'advice card' gives no hint that a question can be supplied or that reversed cards are permitted.

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 phrase 'Single advice card' identifies both the resource (a tarot card) and the shape of the result (one card, advice-oriented), which is more specific than the name alone. However, it does not distinguish this from near-identical siblings such as astroway_tarot_rider_waite_draw_single, _clarify, or _draw_decision, so an agent cannot tell why it would pick this one over those.

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 at all: no statement of what an 'advice' reading is for, no exclusions, and no reference to the many sibling tarot drawing tools. The 'advice' label implies a context but never states one, leaving selection entirely to inference.

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