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

The annotations already declare readOnly/idempotent/non-destructive, lowering the burden, and the description adds useful extras: the default of 'now', the Ketu inclusion, and the 20-credit Tier 2 cost. It still says nothing about rate limits, auth, or response shape, so it is solid but not rich.

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 behavior is front-loaded in one dense sentence, followed by a compact metadata block for group/endpoint/cost. No filler, though the metadata block could be folded or trimmed for tightness.

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 not be explained, and the endpoint/cost lines are useful. However, for an 8-parameter tool with 63% schema coverage and no required params, the definition never explains the date/time pair or resolves the `targetDate` mismatch, leaving ambiguity about the single most important input.

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?

The description references a `targetDate` parameter that does not exist in the schema (which has `date` and `time`), which will mislead an agent about how to supply the moment. With schema coverage at 63% and no format hints for date/time, the description does not compensate for the gap and actively introduces a naming inconsistency.

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+resource: sidereal positions of all 9 grahas including Ketu with the KP sub-lord chain attached. This distinguishes it from the many natal/KP siblings (kp_cusps, kp_sub_lords, kp_significators) by scoping it to transits, 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?

The phrase 'Use for KP transit-timing' gives an implied use case, but there is no when-not, no prerequisite (e.g. birth data vs. just a date), and no named alternative among the ~15 other KP tools. It is adequate but leaves the agent to infer scope boundaries.

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