Yogas: Chandra (Sunapha, Anapha, Durudhara, Kemadruma)

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

Annotations already cover the safety profile (read-only, idempotent, closed-world), so the description's job is the substantive rules: it discloses that Rahu and Ketu are excluded from counting, that each Kemadruma condition is returned separately, and that no result/interpretation text is produced. That is meaningful domain behavior beyond the annotations, though nothing is said about output shape beyond the yoga plus forming planets.

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?

Dense but front-loaded: the yoga definitions come first, cited by verse, followed by exclusions and the output caveat. No filler sentences, though the compressed astrological shorthand and mixed abbreviations are hard to parse on first read.

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?

With an output schema present, the description needn't explain the return shape, and it correctly scopes what is and isn't included (no result text, no Rahu/Ketu). However, for a 13-parameter tool with low schema coverage it omits any guidance on the time/place inputs and on choosing this tool over the full-yoga or dosha siblings.

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 23% across 13 parameters, so the description carries substantial burden but says nothing about date, time, latitude, longitude, timezone handling, ayanamsa selection, or houseSystem. An agent must infer all of that from partially documented schema fields, and the enumerations (houseSystem codes) get no help.

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 the exact resource computed (Chandra yogas from the Moon per BPHS ch. 37) and enumerates the four yogas with their definitions, so an agent knows precisely what comes back. It does not name a sibling such as the full Parashara yoga set or the Kemadruma dosha variant, so sibling differentiation is left to the tool name.

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?

Scope ('counted from the Moon') implicitly tells the agent this is the Moon-based subset rather than a general yoga scan, but there is no explicit when-to-use/when-not, no mention of when to prefer the full Parashara yoga tool or the Kemadruma dosha tool, and no stated prerequisites.

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