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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description usefully adds the cost (10 credits, Tier 1) and the concrete HTTP endpoint, which are beyond the annotations. It says nothing about date-range span behavior, output shape, or failure modes, so it adds only modest context on top of the 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 core purpose is front-loaded in one line, followed by a scannable bracketed metadata block with no filler. Every line conveys something (group, endpoint, required inputs, cost). It is efficiently sized for a metadata-stub style description, though the block format substitutes for real explanation.

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?

For a 20-parameter tool with only 25% schema coverage, the description leaves most configuration semantics undocumented. An output schema exists, so return values need not be described, but the absence of usage context, sibling differentiation, and parameter meaning leaves real gaps an agent must guess at.

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 only 25% across 20 parameters, so the description carries a heavy burden. It merely re-lists the five required parameters already captured in the schema's required array, adding no meaning. It never explains the relationship between date/time and targetDate/targetTime, nor the roles of the enums (zodiacType, houseSystem, ayanamsa) or dial-specific flags.

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 first line states a specific verb+resource+method: transits computed against natal midpoints on a 90° dial. That distinguishes it reasonably well from cosmobiology siblings like dial_90, midpoint_pictures, and witte_formulas. However, it never explicitly names those siblings or contrasts its output with them, so an agent still has to infer the boundary.

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 gives no when-to-use guidance, no prerequisites, and no alternatives. It notes only required params and cost, which are selection-relevant but not usage-directional. An agent cannot tell from this text when transit-midpoints is preferred over transit_calendar or dial_90.

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