Varga D27: Saptavimsamsa

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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds genuinely useful non-schema facts: the HTTP endpoint, the four required inputs, and the cost (20 credits, Tier 2). It says nothing about output shape or accuracy caveats, but an output schema exists, so the remaining gap is modest.

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?

Front-loaded with the chart name and domain, then bracketed metadata for group, endpoint, required inputs and cost. Efficient with no filler; only the redundant 'Required' line duplicates the schema and could be dropped.

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?

For a 13-parameter endpoint with low schema coverage and a dense family of near-identical varga siblings, the description supplies no routing criteria and no explanation of the optional configuration parameters. The cost and endpoint lines help, but an agent still cannot confidently pick this over another divisional-chart tool without outside knowledge.

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?

With 13 parameters and only 23% schema description coverage, the description should carry weight here. Instead it merely restates the four required fields already listed in the schema's required array and says nothing about ayanamsa, timezone, zodiacType, houseSystem, or ayanamsaId — the parameters most likely to change the result.

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 chart (Saptavimsamsa / Bhamsa, D27) and gives its interpretive domain (strengths, weaknesses, stamina), so an agent knows what the tool computes. It does not differentiate it from the ~20 sibling varga tools (d1, d2, d3, d9, d10, d60), so choosing D27 over D9 or D10 rests entirely on the caller's prior knowledge of divisional charts.

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 parenthetical 'strengths, weaknesses, stamina' implies the topical domain where D27 applies, which is more than nothing. There is no explicit when-to-use/when-not guidance and no comparison to the other varga endpoints or to specialized_vedic_divisional, leaving selection largely to inference.

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