Compatibility Horoscope

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

Annotations already indicate read-only, non-destructive, idempotent behavior. Description adds value by specifying output content (strengths, friction, 30-day themes) and cost (50 credits), which annotations do not cover. No contradictions.

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?

Purpose is front-loaded, but the example is overly long and contains a nested JSON structure. The cost and group info are useful but the example is misleading and could be omitted or corrected.

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?

No output schema, yet description only vaguely mentions outputs (strengths, friction, themes). Lacks detail on return structure. Parameter example mismatch further undermines completeness. Agent would lack sufficient context to invoke correctly or interpret results.

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 0% (parameters not described in schema). Description fails to explain 'sign1', 'sign2', 'language', or 'disclaimer_inline'. The provided example uses 'chart1'/'chart2' with date objects, which contradicts the actual schema expecting sign strings, making it misleading.

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?

Description clearly states 'Generate a relationship horoscope based on synastry between two charts' with specific outputs (strengths, friction points, themes) and a 30-day timeframe, distinguishing it from siblings like 'synastry' or 'human_design_compatibility'.

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 on when to choose this tool over alternatives (e.g., 'synastry', 'chinese_zodiac_compatibility'). No exclusions or prerequisite conditions mentioned, leaving the agent to infer usage context.

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