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

Annotations already declare readOnlyHint/idempotent/non-destructive/closed-world, so the safety profile is covered. The description adds genuinely useful behavioral context the annotations lack: the 20-credit Tier 2 cost and the birth-time precision sensitivity. It stops there — no latency, caching, or reliability notes.

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?

Very short and front-loaded: the purpose sentence comes first, followed by structured [Group] and [Cost] tags. No filler, though the single sentence carries little operational detail, which is a completeness issue rather than a conciseness one.

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?

Return values need not be explained since an output schema exists, and annotations cover safety, so the description is not required to carry those. But for a fine-grained Vedic varga tool in a huge sibling family it gives no routing or parameter guidance, leaving the agent to infer differentiation from the name.

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 only 33% across 15 params, so the description must compensate — and it provides zero parameter-level meaning (no mention of date/time formats, timezone, ayanamsa, house system, or the compact-mode fields). At low coverage with no compensating text, this is a clear gap.

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 the specific resource (Shashtiamsa / D60 divisional chart) and adds its interpretive meaning ('past karma, the most subtle divisional'), so an agent knows this computes the D60 varga. It does not, however, explicitly distinguish this from the fifteen other varga_* siblings beyond the inherent D60 label.

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 explicit 'use this instead of D9/D30' routing and no when-not guidance across the large varga family. The one implicit guideline is 'high precision needed in birth time,' which warns the agent that this chart is only meaningful when the birth time is accurate — useful but not a full selection rule.

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