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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint=false, and destructiveHint=false, so the safety profile is covered. The description adds two pieces of context not in the annotations: the group membership and the cost of 10 credits (Tier 1), which is genuinely useful for budgeting. It still says nothing about what the returned card means or how timing is derived, so it adds some but not rich behavioral value.

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?

Extremely short and front-loaded: the purpose line comes first, followed by compact group/cost tags. Nothing is wasted, though the brevity comes at the cost of substance rather than being a virtue of 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, but for a tool with five parameters at 40% schema coverage and no usage guidance, the definition is too thin. An agent knows the theme and the credit cost but not how to frame the question, what the optional parameters do, or when this beats the other timing/draw tools.

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% and the description mentions no parameters at all. Five parameters exist (seed, fields, question, precision, allowReversed) and the description does nothing to explain seed, question, or allowReversed, nor how a 'timing' reading should be phrased. With low coverage the description is expected to 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?

The phrase 'Single timing card to indicate when' conveys the resource (a tarot card draw) and its function (timing indication), and the group tag anchors it to Rider-Waite-Smith. However, it never states the action explicitly (draw/return) and does not distinguish it from siblings like astroway_tarot_rider_waite_draw_single, astroway_tarot_rider_waite_outcome, or astroway_tarot_marseille_timing. Purpose is inferable but under-specified.

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 statement of when not to use it, and no reference to any alternative tool. An agent cannot tell from this text whether to pick this over the marseille timing variant or the general single-card draw. Usage is left entirely to inference.

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