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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so the safety profile is covered. The description adds genuinely useful behavioral context beyond that — the credit cost (10 credits, Tier 1), the endpoint, and the visualization group — but says nothing about rendering constraints, the svg-vs-json default, or output size behavior.

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?

Two front-loaded sentences that state the layout and the house-numbering rule, followed by a compact bracketed metadata block. Nothing is padded, though the endpoint line duplicates information already implied by the tool name.

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, so return values need not be explained, and the parameter surface is fully documented in the schema. The remaining gap is routing: nothing tells the agent when this South Indian wheel is the right choice versus its north/east siblings, which is the main decision an agent faces here.

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%, with the birth-data body, fields, and precision all documented in the schema itself, so the baseline of 3 applies. The description adds no parameter-level meaning beyond what the schema already provides.

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 states a specific verb+resource (render a Vedic wheel) and pins down the exact layout convention that defines the 'South Indian' variant — 4x4 grid, Pisces top-left, fixed signs, house numbers at the lagna sign. That layout detail is what separates it from astroway_render_wheel_vedic_north and _east, though those siblings are never named, so the differentiation is implicit rather than explicit.

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 statement of when to choose this wheel over the north/east Vedic variants or the Western wheel, and no prerequisites or context for use. The layout sentence implies a use case but the agent is left to infer which chart style the user wants.

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