Natal Chart

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

Beyond the annotations (readOnly, idempotent), the description discloses important behavioral details: unknown birth times are accepted as '00:00' without error but yield unreliable lagna results, and a sunrise chart is used when time is omitted. It also explains output format options and the API's lack of flagging for unreliable results, adding significant transparency.

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 well-structured with clear paragraphs for purpose, workflow, input contract, and distinction. It is slightly verbose (e.g., repeating 'BirthData enforces...' when the schema already conveys this), but it front-loads the core purpose and keeps each section relevant. The link to full docs is a good touch, but the length could be trimmed slightly without losing value.

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?

The description covers the essential context: what the tool does, how to use it, the unknown-time caveat, and a link to the full output/error contract. It does not enumerate the exact return fields, but that is available via the linked docs and the output schema reference. It is fairly complete for a tool with this complexity, though a bit more detail on common error scenarios would elevate it.

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 input schema already provides thorough descriptions for all parameters, including formats, enums, defaults, and constraints. The description adds minimal extra semantic value beyond what is in the schema, such as noting the ayanamsa enum is 'local (Pydantic)' and pointing to a documentation link. This aligns with the baseline of 3 given full schema coverage.

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 clearly states the tool's function: 'Computes the full sidereal natal chart from BirthData and returns planet rows, houses, aspects, arudhas, upapada, bhava cusps, and avakhada metadata.' This is a specific verb (computes) with a clear resource (sidereal natal chart) and distinguishes it from the divisional chart sibling.

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 explicitly contrasts with 'asterwise_get_divisional_chart' by noting 'sixteen vargas only, not the primary radix bundle returned here.' Additionally, it provides workflow context ('BEFORE: None... AFTER: RECOMMENDED — asterwise_get_yogas'), guiding when this tool fits in a sequence.

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