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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description contributes the credit cost (20 credits, Tier 2) and endpoint, which are useful but not behavioral traits like edge cases or precision loss beyond the schema's note.

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?

Front-loaded with the return content, followed by the use case, with metadata in a compact bracketed block. Efficient, though the metadata block slightly dilutes the core sentence.

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 description covers the required param, cost tier, and endpoint. The only shortfall is the lack of sibling disambiguation among several closely named KP tools.

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 coverage is 67%, and the schema already documents `fields` and `precision`. The description adds the 'sidereal' qualifier for longitude beyond the raw 0..360 range, a small but real semantic gain; nothing is said about the compact-mode parameters, so it doesn't compensate for the gap.

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: 'Returns the full sub-lord chain (sign/star/sub/sub-sub) at any sidereal longitude 0..360.' An agent can distinguish this from the sibling kp_sub_lords (which operates on a chart/planet) because this one is longitude-scoped.

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?

It names use cases ('transit-trigger and dasha-bhukti exact-moment analysis') but gives no when-not guidance and never contrasts itself with the related kp_sub_lords or kp_asc_sub siblings, leaving the agent to infer which KP sub-lord tool applies.

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