KP: Placidus cusps with sub-lord chain

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

Annotations already cover safety (readOnly, idempotent, non-destructive), so the description is not obligated to repeat that. It adds genuinely useful context beyond annotations: the endpoint, the credit cost and tier, and the authoritative source (K.S. Krishnamurti 1971 Vimshottari proportional sub-divisions), which tells the agent the output is deterministic and canonically defined.

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 front-loaded sentences on what is returned, followed by compact metadata tags for group, endpoint, required inputs and cost. Nothing is padded, though the bracketed tags are scaffolding rather than description.

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. But for a 13-parameter tool with 23% schema coverage, the description leaves too much unsaid about the optional inputs that materially change output (ayanamsa school, house system, timezone handling). Given the complexity, it is under-specified.

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 low (23%) and the required list (date, time, latitude, longitude) merely restates what the schema already marks required. Thirteen parameters exist, including enums like houseSystem and zodiacType and an undocumented ayanamsaId, yet the description adds no meaning for ayanamsa, timezone, houseSystem or cosmogram. It does not compensate for the coverage 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?

The description states a specific verb+resource: 'KP-canonical Placidus cusps (12) with full sub-lord chain (sign / star / sub / sub-sub) for each cusp.' That is clear and signals it is a per-cusp chain rather than a planetary one, implicitly separating it from astroway_vedic_kp_sub_lords and astroway_vedic_kp_asc_sub. However it never names those siblings, so the distinction is inferred rather than explicit.

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?

Usage is only implied by the KP/Vedic framing; nothing states when to choose this over astroway_vedic_kp_sub_lords, astroway_vedic_kp_asc_sub or astroway_vedic_kp_planet_cuspal_position. The required-parameter tag helps an agent get inputs right but is not usage guidance.

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