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

Beyond the readOnly/idempotent annotations, the description discloses meaningful behavior: deterministic scoring, breakdown and weights, cap on failed mandatory rules, best-window and avoid-windows, and the 'data only — caller writes recommendation' boundary. This gives the agent an accurate model of what the tool returns and how it behaves.

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?

The description is dense but front-loaded with the core purpose and then packed with useful behavioral details. The event_type enum list is redundant with the schema, but the rest of the content earns its place for a complex astrological tool.

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?

With no output schema, the description does a good job listing the outputs: ranked candidates with breakdown and weights, Abhijit/clean best-window, and Rahu/Gulika/Yamaganda avoid-windows. It could be more explicit about response shape or edge cases, but it is sufficient 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 100%, so the input schema already documents all 17 parameters. The description restates the event_type enum but adds no new parameter-level meaning beyond what the schema provides, so the baseline 3 applies.

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 uses a specific verb and resource: 'Find auspicious dates for an event across a date range' and explains the system ranks dates by classical rules. It distinguishes the tool from get_gochara_range by noting this tool returns ranked candidates while the sibling gives raw per-day details.

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?

Explicitly provides an alternative: 'Use get_gochara_range instead to get raw per-day details and decide yourself.' It also clarifies the tool is data-only and the caller writes the recommendation, preventing misuse of the result as a final recommendation.

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