Gemstone (ratna) recommendation

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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds real behavioral context: the response always names the school used, and the two schools agree on the three gems but differ on withholding and ordering. It says nothing beyond that about response shape or the 20-credit cost being incurred per call.

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 sentences, front-loaded with the answer the tool produces, then the school distinction. No filler, and every clause carries information used to interpret the response.

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 readOnly/idempotent annotations and an output schema present, the description need not explain return values, and it does cover the key interpretive choice (school). The remaining gap is sibling disambiguation against the navaratna and gemstone-report tools.

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 100% and the nested body/school fields are documented, so baseline would be 3. The description earns a step up by explaining what each school actually prescribes (1st/9th/5th lords versus classifying grahas by owned houses, naming the yogakaraka and functional malefics), which is domain meaning the enum text does not fully convey.

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 and resource: which of the nine gems to wear, derived from the sidereal lagna, and names the two prescription schools. It is clear what the tool returns, but never distinguishes itself from close siblings such as astroway_vedic_gemstones_navaratna, astroway_reports_gemstone or astroway_esoteric_crystals_recommend.

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 description explains how the schools differ and that lagna-lord is the default, which implicitly guides the school choice, but it gives no explicit when-to-use guidance, no conditions that would pick this tool over the gemstone siblings, and no prerequisites (e.g. that a birth chart is required).

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