Rubeus — Red

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

Annotations already declare readOnlyHint=true, destructiveHint=false, idempotentHint=true, so the safety profile is clear. The description adds the note 'ill omen' but does not supplement behavioral details like return format or required permissions. It does not contradict annotations, but adds minimal 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?

The description is very short (three sentences), which is concise but at the expense of missing critical information. It is structured with a poetic line and a group label, but lacks a clear functional statement.

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 large sibling set (many geomancy figures), the description is incomplete. It does not explain the tool's output, input requirements beyond an empty example, or how it differs from other geomancy tools. No output schema further limits completeness.

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 100% coverage for the 'body' parameter, but the description only provides an empty example '{}' and no additional semantic meaning. It does not clarify what fields are expected inside 'body' beyond the generic schema note, so the description adds little value.

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 'Passion, anger, blood — ill omen' merely restates the symbolic meaning of the Rubeus figure without stating what the tool does (e.g., 'returns the interpretation of the Rubeus geomancy figure'). It is a tautology of the title and does not clarify the tool's function or distinguish it from sibling geomancy tools.

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 guidance is provided on when to use this tool versus sibling geomancy tools or other tools. There is no mention of context, prerequisites, or alternatives.

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