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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description usefully adds cost (20 credits, Tier 2) and the group tag, which is real behavioral context, but says nothing about response shape, computation cost, or date-range handling beyond that.

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?

Extremely tight and front-loaded: the identity phrase comes first, with group and cost as bracketed metadata. Nothing is padded, though the brevity verges on under-specification for a tool with four sibling levels.

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 and annotations cover safety, and parameters are fully documented, so the burden on the description is modest. Still, a tool sitting in a 5-tool tribhagi ladder should let an agent distinguish it from its siblings in prose, and this does so only weakly.

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 body schema extensively documents date/time/lat/lon, timezone handling, houseSystem letters and compact-mode fields. The description adds no parameter-level information, so the baseline of 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 largely restates the name/title ("Tribhagi Pranadasha") and adds only one substantive phrase, "5-level cascade (finest grain)." That phrase does hint at the depth level versus the coarser tribhagi siblings (maha/antar/pratyantar/sookshma), but it never states what output the tool produces or what a pranadasha period represents.

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?

No when-to-use guidance is present. With five sibling levels in the tribhagi family alone, the agent gets no explicit rule for choosing prana over sookshma or pratyantar; "finest grain" is the only implicit cue and it is not framed as selection criteria.

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