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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. The description adds the credit cost (20 credits, Tier 2) and group label, which is useful operational context, but it does not disclose that sect is derived from the chart, the default period-length behavior, or any limits on the returned span.

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?

One front-loaded sentence naming the verb, resource and domain, followed by two bracketed metadata tags. Nothing is redundant and the essential concept arrives first.

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 an output schema present, return values need no explanation, and the input schema is fully documented. The description is adequate for invoking the tool; the only real gap is guidance on the computed span and how sect influences results, which is minor given the schema's depth.

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 100% and the nested body schema is unusually thorough (format constraints, ayanamsa, timezone handling, houseSystem letters). The description adds nothing about maxYears duration or fields/precision compact-mode parameters, so baseline 3 applies with the schema doing all the work.

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 (Calculate) and a specific resource (Firdaria planetary periods), then defines the technique as the traditional Persian time-lord system based on sect and planet order. An agent knows exactly what this produces, though it does not explicitly distinguish itself from prognostic siblings like profections or primary directions.

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?

There is no indication of when to choose this over the many other prognostics tools (profections, primary directions, progressions, returns). The description explains what Firdaria is but never states the use case, prerequisites, or exclusions, leaving the agent to infer routing.

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