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

Annotations already mark the tool as read-only and non-destructive. The description adds meaningful behavioral detail by enumerating what each returned aspect includes (type, orb, applying/separating status, narrative interpretation, impact rating, practical guidance) and noting that both current and future dates are supported. It does not discuss caveats or rate limits, but for a safe read operation this is good transparency beyond structured fields.

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 first two sentences immediately define the core behavior and return content. The final keyword-style sentence ('Transit aspects API, transit-to-natal analysis, predictive astrology...') adds little for an agent and could be removed without loss, but it does not obscure the core meaning or appear early. Slightly overstated length for the edge value, but mostly efficient.

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?

There is no output schema, so the description productively enumerates return fields and mentions that supports filtering and default/future dates. With 9 parameters, nested natal chart objects, and rich sibling alternatives, the description does not cover every possible open question, but it gives enough to correctly select and call this endpoint for detailed transit interpretations.

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 every parameter has its own description, so the schema carries the semantics. The tool description adds no parameter-specific detail beyond confirming that planets and aspectTypes can be filtered. This is exactly the baseline 3 case: the schema already covers the parametric meaning, so the description is not required to compensate but also doesn't enrich it.

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 opens with a concrete verb and resource: 'Calculate all transit-to-natal aspects' and immediately clarifies the exact inputs (transiting positions vs. natal chart). It distinguishes the tool from the sibling /transits endpoint by highlighting added interpretation fields, strength ratings, and timing guidance, which resolves ambiguity among the large post_astrology_* sibling set.

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 sets clear usage context: it is for detailed transit-to-natal aspect analysis with narrative interpretations and filtering. It explicitly positions itself as 'more detailed than the /transits endpoint,' which helps an agent choose among this, post_astrology_transits, and post_astrology_transits_monthly. It stops short of stating when to pick an alternative or when not to use this endpoint, so no exclusions are given.

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