ephemeris_transits

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

The description goes beyond annotations (readOnlyHint and destructiveHint) by detailing internal behavior: it calculates natal longitudes, searches for exact transits, costs 6 credits plus potential extra for long runs, and silently clamps search ranges. These details are valuable and not contradicted by 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?

The description is well-structured with clear section headings and front-loaded purpose. However, it is somewhat lengthy (multiple paragraphs) and could be slightly more concise without losing essential information. Every part is informative, but there is minor redundancy.

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?

Despite lacking an output schema, the description mentions returning 'a list of exact transit moments' but does not detail the structure of those moments (e.g., planet names, aspect types, timestamps). Given the complexity and depth of other details, this omission is a gap, though the tool is still usable.

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?

With 100% schema coverage, the description adds significant value by explaining the impact of omitting optional arrays, showing how aspect_angle modifies search targets, and giving specific examples for transiting_planets and natal_points. This enriches the parameter understanding beyond the schema's descriptions.

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 tool's purpose: searching for exact transit moments affecting a natal chart. It uses a specific verb ('Search') and resource ('astrological transit events') and distinguishes itself by detailing its internal workings and providing examples. Although it does not explicitly compare with sibling tools like 'ephemeris_natal_transits', the purpose is unmistakable.

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?

The description provides extensive usage guidance, including a 'HOW IT WORKS' section, aspect angle explanations, supported bodies, credit cost, search range limits, and a concrete example. It explicitly states ideal use cases ('horoscope timelines, event forecasting, timing windows') and gives examples for common queries like Saturn Return. No alternatives are named, but the guidance is thorough enough to avoid misuse.

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