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

Annotations already declare this a read-only, idempotent, non-destructive, closed-world call, so the safety burden is light. The description adds genuinely useful non-structural context: 50 credits (Tier 3) cost, the POST endpoint, and the domain rule that Friday is excluded per Yatra prakarana plus the preferred nakshatra set. It says nothing about rate limits or response shape, though an output schema exists to cover the latter.

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 purpose and scope, followed by the differentiator, the nakshatra rule, and then a compact bracketed metadata block. Every line carries information; the nakshatra enumeration is long but domain-relevant. Minor overhead comes from the endpoint string, which is not actionable for a tool call.

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?

Output schema exists, so return values need no explanation, and the domain selection rules are well stated. The gap is input completeness: with 10 parameters at 40% coverage, the description never explains that latitude/longitude (defaulting to 0) determine location-specific windows, nor the ayanamsaId alias, leaving correctness of a computational tool partly undocumented.

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 10 parameters and only 40% schema description coverage, the description should compensate for the undocumented ones, but it only repeats that search_window_start is required. Latitude/longitude, search_window_end, topN, and ayanamsaId have no descriptions in either the schema or the description, so the agent gets no guidance on location-dependence or the ayanamsaId/ayanamsa duality. Only the required-parameter note adds marginal value over the schema.

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 multi-day journeys (pilgrimages, relocation travel)', which is clearly a muhurat computation, not a chart lookup. It differentiates against short travel ('stricter than short travel', Friday excluded), but never names the sibling astroway_vedic_muhurat_travel, so an agent must infer which of the many sibling tools is the alternative.

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?

Gives clear context for use: multi-day journeys, pilgrimages, relocation travel, and implicitly excludes short trips by claiming to be stricter than the short-travel variant. The metadata block also states the one required parameter and the credit cost, which helps an agent decide whether to call it. However, it never explicitly says 'use astroway_vedic_muhurat_travel for single-day trips', so routing is implied rather than directed.

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