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

Annotations already declare read-only, idempotent, non-destructive and closed-world. The description adds real behavioral value beyond them: the scoring criteria (lord dignity, benefic/malefic placement, Moon condition, activity-karaka, prohibited-period overlap), the fail-reason visibility behavior, the API-key tier limit, and the important 'draft rules, never a guarantee' caveat.

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?

Two dense sentences that front-load the core purpose and follow with scope, scoring, and caveats. Every clause carries information, though the second sentence is a long comma-separated list that could be tightened.

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 no explanation, and annotations cover the safety profile. The description supplies scope, scoring methodology, failure behavior, and the non-guarantee caveat — enough for correct invocation, with the main gap being undocumented non-required parameters.

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 33% across 9 parameters, so the description must compensate and largely does not. It ties 'days' to the 1-day/3-day API-key cap, which is useful, but leaves limit, startDate, activity, place, and the coordinate/timezone fallback unexplained beyond the schema itself.

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 — 'finds ascendant-sign windows' — and pins down the exact domain ('elected Lagna') that separates it from siblings like find_muhurta and find_marriage_windows. It also discloses the scoring dimensions, so an agent knows precisely what the tool produces.

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?

Labels itself 'EXPERT electional search' and gives the day-range/API-key constraint plus the fact that ineligible windows remain visible with fail reasons, which implies a professional electional workflow. However it never explicitly says when to choose this over find_muhurta or find_muhurta_with_natal_fit, so the agent must infer the boundary.

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