Panchang: Tithi

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

Annotations already declare readOnly/idempotent/non-destructive, so safety is covered; the description adds genuine context beyond that — the computed quantity, the returned payload components (paksha, tithi name, % complete), and the credit cost of 20 (Tier 2), which matters for a metered API. It omits auth requirements or failure modes, but for a pure read-only computation this is solid.

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 core sentence is front-loaded and dense — formula, range, and return fields in one line. The bracketed metadata block is compact and each line carries information, though restating the required parameters duplicates what the schema's `required` array already declares.

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?

For a computational endpoint with an output schema, the description needn't explain return values but does briefly, and it names required inputs, the endpoint, the cost, and the group. An agent has everything needed to construct a valid call; the only real gap is sibling disambiguation, which is scored elsewhere.

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?

With only 23% schema description coverage across 13 parameters, the description carries real weight, and it does list the four required inputs (date, time, latitude, longitude). However, it says nothing about the many optional parameters (ayanamsa/ayanamsaId interplay, zodiacType, houseSystem, cosmogram, city, name), and none of the listed required params get format or semantics explanation.

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 combination — computes the tithi (lunar day 1-30) via Moon-Sun elongation divided by 12° — and names the returned fields. It is distinguishable from siblings like panchang_karana or panchang_yoga by naming the specific panchang limb, though it never explicitly contrasts itself with astroway_vedic_panchang_full or astroway_calendar_moon_phase.

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?

Usage is implied by the [Group: Vedic] tag and the panchang-prefixed siblings, but there is no explicit guidance on when to call this versus the aggregate panchang_full or the western moon_phase tool. No exclusions or prerequisites are stated, leaving the agent to infer the choice from the name alone.

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