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

With no annotations, the description carries the full disclosure burden. It does explain what is computed and roughly what comes back, which is more than nothing, but it says nothing about determinism, side effects, the timezone assumption underlying the inputs, or whether the two charts must share a timezone — relevant context for a 15-parameter computation.

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 core purpose, then cleanly labeled WHEN TO USE / WHAT IT DOES / RETURNS blocks. The RETURNS section is partly redundant with the output schema, but the whole thing stays tight and scannable.

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?

Purpose and output shape are covered, and an output schema exists so return values need no elaboration. However, for a tool with 14 required parameters and zero schema documentation, the description should at minimum explain the dual-birth-detail input contract and the timezone default; that gap is the main incompleteness.

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 0% and the description explains none of the 15 parameters. Field names like year1/lat1/minute2 are mostly self-evident, but the description never states that two full sets of birth date/time/coordinates are required, nor does it clarify tz_offset semantics or that its 5.5 default is India Standard Time — a significant omission for global inputs.

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 (Calculate) and resource (Vedic compatibility / Kundli matching) plus the named framework (Ashtakoota, Guna Milan, Manglik dosha, Nadi). Among siblings full of single-chart tools (calculate_birth_chart, calculate_varga_charts, calculate_yogas), this is the only two-person relationship tool, so it is trivially distinguishable.

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 explicit WHEN TO USE line gives a clear triggering condition (an agent needs to evaluate relationship compatibility). It does not name an alternative or an exclusion, but no sibling performs compatibility scoring, so there is little ambiguity to resolve.

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