Rune by Zodiac

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

Annotations already declare the tool as read-only, idempotent, and non-destructive. The description adds no behavioral context beyond the purpose. It does not describe output format, error handling, or any side effects, which is acceptable for a simple lookup but still minimal.

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 description is very concise with the key purpose front-loaded. It includes a group tag and example request. However, it could be slightly more structured (e.g., explicitly listing input/output).

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?

Given the tool's simplicity (single enum parameter, no output schema), the description provides the essential information. However, the lack of output format details (e.g., what is returned) leaves some ambiguity for the agent.

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?

The input schema has no descriptions (0% coverage), so the description must compensate. It clarifies that 'sign' uses tropical zodiac and provides an example request. The term 'affinity rune' adds slight semantic nuance. This is adequate but not exceptional.

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 clearly states the purpose: mapping a tropical zodiac sign to its Elder Futhark affinity rune. It is specific and distinct from sibling tools like 'runes' or 'runes_single', which do not involve zodiac signs.

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?

No explicit guidance on when to use this tool vs alternatives. The description does not mention exclusions or compare with sibling rune tools. The group tag 'Elder Futhark Runes' is present but insufficient for decision-making.

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