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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), so the description earns credit by adding operational context: endpoint, cost (50 credits, Tier 3), and the required parameter. It could go further on what the scan returns and window bounds, but the cost/auth context is genuinely useful.

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-loads the purpose, then compact structured brackets for group/endpoint/required/cost, plus a tight nakshatra list. Every line carries signal; only minor trimming possible.

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 values need not be described, and the description supplies the domain-specific auspiciousness rules that an agent would otherwise lack. The remaining gap is parameter-level guidance on the non-required inputs, which is modest given schema coverage.

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 only 40% and the description adds no parameter semantics beyond restating the required 'search_window_start'. It says nothing about topN, latitude/longitude, timezoneOffset, or search_window_end, so it fails to compensate for the coverage gap on a 10-parameter tool.

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+resource: an 'auspicious-window scanner' for 'starting formal education / Vidyarambha ceremony'. The education/Vidyarambha framing cleanly distinguishes it from the many sibling muhurat tools (marriage, business_start, travel, etc.) without opening either schema.

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?

Provides domain rules for a good window (preferred nakshatras, avoid Sun/Tue/Sat) and lists the required input, but never states when to choose this tool over a sibling like naming_ceremony or general_auspicious. Guidance is implied rather than explicit about tool selection or exclusions.

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