Norn 3-Rune Cast

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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds genuinely useful non-schema context: a cost of 10 credits (Tier 1) and the POST endpoint. It does not explain what the cast returns or how seeding affects repeatability, but with annotations carrying safety and an output schema present, a 3 is fair.

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 spread definition is front-loaded and the metadata lines are compact. The Group/Endpoint/Cost lines are boilerplate but the cost line earns its place; nothing is padded.

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. But for a parameterized divination tool with three wholly undocumented inputs and no sibling differentiation, the description leaves an agent unable to configure a call confidently.

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?

Three parameters exist with 0% schema description coverage, and the description mentions none of them. Notably 'allowReversed' (default true) and 'seed' have meaningful semantics — whether reversed runes can appear, and determinism of the draw — that are completely unexplained, forcing the agent to guess.

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 as a Past/Present/Future (Urdr/Verdandi/Skuld) three-rune layout, and the title supplies the verb 'Cast'. However, it never states what the tool actually returns (a 3-position Futhark draw) as a sentence, and it does not distinguish itself from the sibling rune tools (astroway_runes_single, astroway_runes_nine, astroway_runes_runes) beyond the implicit number 'three'.

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 to choose a three-rune spread over the single-rune or nine-rune siblings, nor any prerequisite or exclusion. An agent must infer selection purely from name numerology.

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