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

Annotations already declare readOnly/idempotent/non-destructive, so safety is covered. The description adds the 10-credit cost and group tier, which is genuinely useful for an agent budgeting calls, but says nothing about what the draw produces or whether the question parameter affects randomness.

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 text is short and front-loads the purpose, but the second block is pure metadata and the first sentence is too thin to be considered efficient rather than under-specified.

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, but for a tool embedded in a huge tarot family the description leaves purpose, selection criteria, and parameter meaning unresolved. It is not complete enough to call correctly without further exploration.

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 40%, and the description explains none of the 5 parameters (seed, question, fields, precision, allowReversed). 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?

"Single timing card" identifies a resource (one tarot card) and an implied purpose (timing questions), but offers no verb and no differentiation from siblings such as astroway_tarot_marseille_draw_single or astroway_tarot_rider_waite_timing. An agent must infer the distinction from the name alone.

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 pick this over the many sibling draws (draw_single, draw_decision, draw_career) or over rider_waite_timing. The only extra context is group and credit-cost metadata, which does not help selection.

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