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

Annotations already declare readOnly/idempotent/non-destructive, so the bar is lower, and the description adds real value: the exact classical sources used, the preferred nakshatra list, the Sun/Tue/Sat avoidance rule, and the fact that output is top-N days sorted by score. It omits operational context such as credit cost and that latitude/longitude/timezone defaults will silently affect the result.

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 evidence for the scoring method. The 11-name nakshatra enumeration is long but defensible as domain transparency; otherwise the text is dense with little waste.

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?

An output schema exists, so return structure need not be explained, and annotations cover the safety profile. For a 10-parameter, 40%-documented, domain-heavy tool, though, the description leaves location/timezone handling and cost unaddressed, which is a meaningful gap for correct invocation.

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 only 40% across 10 parameters. The description compensates for the two conceptually important ones — the date range and top-N ranking — but says nothing about latitude/longitude/timezone, which are essential for a sunrise-anchored muhurat scan, and ayanamsaId is undocumented in both places.

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 — an auspicious-window scanner for marriage (Vivah Muhurat) over a date range — and the scoring basis (Tithi, Vara, Nakshatra, Yoga, Karana). This cleanly separates it from the many sibling muhurat variants (business_start, property_purchase, general_auspicious) whose only differentiator is the event type.

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 implies usage well: give a date range, get scored candidate days. However it never states when to prefer this over astroway_vedic_muhurat_general_auspicious or astroway_reports_muhurta, nor any prerequisites (location/timezone needed for sunrise-based windows). Usage is inferable but not spelled out.

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