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

Annotations already cover read-only, idempotent, non-destructive and closed-world traits. The description adds genuine value beyond them by disclosing the computation (Jupiter transit plus Vimshottari dasha overlap) and, importantly, that results are planning windows rather than predictions - a caveat an agent needs to avoid overclaiming.

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?

Two tight sentences with the mechanism front-loaded and the output caveat second. No filler or restatement of the title.

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 need no explanation, and the purpose plus caveat are clear. However, for a 10-parameter astrological computation with 0% schema coverage, the description leaves the agent without guidance on required birth-data inputs or how windows are bounded.

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% across 10 parameters, and the description supplies no parameter meaning at all. It never explains date, time, startDate, place, latitude/longitude/timezone, or the years default, so the agent must infer birth-data semantics from field names alone.

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 and resource with unusual precision: overlaps between Jupiter transiting the natal seventh sign and Venus/seventh-lord Vimshottari periods. This mechanism is naturally distinguishable from structural siblings like analyze_marriage_structure or get_marriage_readiness, though no sibling is named explicitly.

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?

There is no when-to-use guidance and no routing to alternatives. The closing caveat ('never a guaranteed marriage prediction') frames interpretation of the output but does not tell the agent when this tool is the right choice versus analyze_marriage_structure or get_marriage_readiness.

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