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

Beyond the annotations (which only establish read-only, closed-world, non-idempotent, non-destructive), the description discloses two valuable operational facts: a quota of up to 3 answers per chart per 6 hours shared across three tools, and the privacy handling of birth details via a one-way code retained 6 hours. It does not describe the response shape or latency, but for a read-only astrology lookup this is substantial added context.

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 capability statement is front-loaded and dense but readable, and the quota/privacy clauses are genuinely useful rather than filler. The final two sentences are slightly verbose and repetitive (both restate the 6-hour retention window), which keeps it from a 5.

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 carries the full burden of explaining returns, and it does so concretely: the running chapter and sub-chapter with month and year, plain-language planet meanings, houses, life areas, and the next sub-chapter start. Rate limits and privacy handling are also covered, leaving no major gap for an agent calling a 3-parameter read tool.

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?

All three parameters are fully documented in the schema, including date format, 24-hour time format, and the 24-hour validity of place_token from find_birthplace. The description adds nothing per-parameter beyond stating that birth details are used only for calculation. At 100% schema coverage 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 names a specific resource — the Vimshottari mahadasha and antardasha running today — and enumerates what the answer contains (planets, their houses, life areas, next sub-chapter start date). It also bounds scope with 'finer periods are not included', which separates it from a full dasha listing. It stops short of explicitly contrasting itself with chart_overview or life_area, only noting they share a quota.

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?

The scoping line 'finer periods are not included' implicitly tells an agent when this tool is sufficient versus needing a deeper period tool. However, no explicit when-to-use guidance against chart_overview or life_area is given, and those siblings are mentioned only in the context of a shared quota rather than as alternatives. The agent must infer selection criteria.

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