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 by structured data. The description adds the cost tier (Tier 2, 20 credits) and the group (Vedic), which are useful operational facts not present in annotations. However, it does not disclose behavioral specifics like how ayanamsa defaults interact with the KP system, or whether KP-specific defaults are applied, which matters because the tool is KP-specific and the schema exposes many configurable sidereal options.

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 description is a single dense sentence plus two bracketed metadata lines. It is front-loaded with what the tool returns and wastes no words. The bracket notation for group and cost is compact and parseable, though it is slightly unconventional and the cost figure is stated as a cost rather than being more explicitly framed as a usage constraint.

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 the description need not enumerate return fields. But for a 15-parameter, KP-specialized tool with low schema coverage, the description omits essential context: it does not state that the KP ayanamsa option should be used, does not explain the KP house system implications, and offers no guidance on coordinate/time requirements. Given the complexity, the definition is materially incomplete for correct invocation.

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%. Only a handful of the 15 parameters (fields, precision, ayanamsa, timezone, timezoneOffset) carry descriptions in the schema. The description itself adds no parameter information at all — it does not clarify which ayanamsa is appropriate for KP (the krishnamurti/kp enum value exists but the description never mentions it), nor does it explain the required date/time/lat/long inputs. With low coverage and no compensating description, the definition leaves most parameters to schema-only interpretation.

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 a specific output: the sub-lord chain for every cusp plus every planet, including lagna and 9 grahas (Ketu named). That distinguishes it clearly from neighboring KP tools like kp_cusps, kp_significators, or kp_sub_sub_lord, which cover different KP constructs. It does not explicitly name those siblings as alternatives, but the scope statement is precise enough that an agent can identify what the tool 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 'horoscope at a glance' implies a survey/snapshot use case, but there is no explicit when-to-use or when-not-to-use guidance, and no sibling alternative is named (e.g., kp_significators for house rulership, kp_sub_sub_lord for deeper subdivision). Usage is inferable but not spelled out.

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