Synastry Interpretation

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

Annotations already declare the safety profile (readOnly, non-destructive, non-idempotent, open-world), so the bar is lower. The description adds genuinely non-inferable cost context — 100 credits, Tier 4 — which matters for an AI-generated call, plus the endpoint and group. It does not mention latency, output length, or auth needs, but the cost disclosure is a real behavioral contribution.

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?

A single front-loaded sentence stating the capability and its content areas, followed by compact metadata lines for group, endpoint, and cost. Nothing is wasted and nothing is buried.

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?

The tool has a deep nested schema and an output schema, so parameter and return-value documentation are largely covered elsewhere, and cost is disclosed. What is missing is routing context against the many synastry siblings and any sense of output length or latency for a 100-credit call, which leaves the definition adequate but incomplete for a crowded toolset.

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 100%, and the nested chart1/chart2 definitions document date/time/latitude/longitude formats, timezone handling, and house-system letters in detail. The description only implies 'two charts' and adds no syntax or format meaning beyond the schema, so baseline 3 is appropriate.

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 names a specific verb and resource — an AI interpretation of synastry between two charts — and enumerates the content it covers (dynamics, attractions, friction, long-term outlook). It does not, however, distinguish itself from closely related siblings such as astroway_relational_synastry (raw synastry data) or astroway_reports_ai_synastry_narrative (AI narrative report), leaving the agent to infer which of the three to call.

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 is given, and no alternative is named. The description only says what the output covers; an agent cannot tell from it whether to call this or the cheaper relational_synastry computation first.

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