Single Rune Draw

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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds genuine value with 'deterministic' (reinforcing idempotency/reproducibility) and the 10-credit Tier 1 cost, plus the endpoint. It says nothing, however, about how the draw behaves with a seed versus without one.

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?

Front-loaded with the core statement in a single short sentence; the bracketed metadata lines are compact and don't bury the payload. It is arguably too terse rather than too long, but nothing is wasted.

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, and annotations cover the safety profile for a parameterless-required read tool. Still, with zero parameter documentation and no guidance on seed reproducibility or single-versus-multi-rune choice, the description leaves real gaps for a 3-parameter tool.

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 0% and all three parameters (date, seed, allowReversed) are unexplained. 'Deterministic' faintly gestures at seed reproducibility, but the description never explains what seed does, whether allowReversed can produce reversed runes, or how date is interpreted.

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 and resource with scope: a single-rune draw, explicitly qualified as deterministic. That distinguishes it in principle from astroway_runes_three and astroway_runes_nine, but the description never names those siblings, so the agent must infer the distinction from the names.

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 statement of when a one-rune draw is appropriate versus a three- or nine-rune spread, and no prerequisites or exclusions. The cost line ('10 credits, Tier 1') is billing metadata, not usage guidance.

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