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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description usefully adds the cost (20 credits, Tier 2), the HTTP endpoint, and the required inputs, which help an agent decide whether to call it, but it says nothing about determinism or output shape beyond that.

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 definition is front-loaded with the concept and its astrological role, followed by compact bracketed metadata blocks (group, endpoint, required, cost). Every line carries information and there is no filler, though the concept sentence could be tightened into an action statement.

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?

With an output schema present and annotations covering safety, the description supplies what an agent needs to invoke it correctly: purpose, required coordinates/date/time, endpoint, and cost. The main gap is guidance on the many optional calculation settings (ayanamsa, zodiacType, houseSystem) that materially affect results.

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 33% across 15 parameters, so the description should compensate, yet it only restates the four required fields (date, time, latitude, longitude) that the schema's `required` array already lists. Optional parameters like ayanamsa, zodiacType, houseSystem, and the compact-mode fields get no semantic help from the description.

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 the specific artifact (Upapada Lagna, UL = A12), defines it concretely as the pada of the 12th house from lagna, and states its role as the Jaimini significator for spouse, marriage, and partnerships. An agent can tell this apart from generic 'padas' or 'karakas' siblings, though no sibling is named explicitly and it describes the concept more than the action ('computes/returns').

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 phrase 'canonical significator for spouse, marriage, partnerships' implies the domain in which to reach for this tool, but there is no explicit when-to-use framing, no prerequisites, and no routing to alternatives such as the compatibility or karakamsa tools that overlap in subject matter.

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