Compatibility Horoscope

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

Annotations already declare readOnly/idempotent/non-destructive/closed-world, and the description adds genuinely useful non-schema context: the 50-credit Tier 3 cost, the REST endpoint, and the 30-day scope of the output. It stops short of explaining caching behavior or whether results are deterministic for a sign pair, but the cost disclosure alone is real value an agent cannot get from annotations.

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 one sentence that matters, then compact bracketed metadata lines. No wasted prose; the cost and endpoint tags each carry independent information an agent needs.

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 needn't be described, and annotations cover the safety profile, which keeps the bar low. What is missing is disambiguation from the crowded compatibility family and any clarification that inputs are sun signs rather than full birth charts — a gap that could cause an agent to call this instead of astroway_relational_synastry when real chart data is required.

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%, so the description carries the full burden — yet it only repeats '[Required: sign1, sign2]', which the schema already declares. The meaning of 'language' must be inferred from the enum list, and 'disclaimer_inline' (boolean, default false) is not explained at all: an agent cannot tell what text it injects or why it would opt in.

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 ('generate') and resource ('relationship horoscope') and enumerates the returned content (strengths, friction points, 30-day themes), so an agent knows exactly what comes back. However, it says 'synastry between two charts' while the parameters are only sun signs, and it never distinguishes itself from the many sibling compatibility tools (relational_synastry, relational_match_score, ai_interpret_synastry, reports_synastry, chinese_zodiac_compatibility, mayan_compatibility, vedic_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 when-to-use or when-not-to-use guidance, no prerequisites, and no named alternative. In a catalog with dozens of compatibility/synastry tools, the agent is left to infer that this is the lightweight sun-sign variant, which is exactly the decision it needs help with.

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