Vedic Wheel: South Indian (SVG)

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 adds useful context with the credit cost (10 credits, Tier 1). It omits the one behavior an agent would most likely trip on: options.format defaults to 'json', so the tool does not return SVG unless explicitly asked, despite the '(SVG)' title. With strong annotation coverage, a 3 is appropriate.

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 tight sentences plus a compact metadata block (group, endpoint, cost); no padding and the distinguishing layout detail is front-loaded. The only waste is that the sentences describe appearance while leaving the actual operation implicit.

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-value detail is not required, and the layout note is genuinely useful. But for a visualization tool sitting among many render siblings, the description leaves out how to get SVG vs JSON output and when this style is preferred over north/east wheels, which are the two facts an agent most needs before calling it.

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 nested body/options properties carry very detailed prose (timezone handling, houseSystem letters, theme css variables, labels), so the schema does the heavy lifting. The description adds nothing about the single body parameter or about setting format/theme/bodies, so 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 the specific output artifact and its defining layout ('South Indian 4×4 grid layout (Pisces top-left, signs fixed)') plus the lagna-placement rule, which is exactly what separates a South Indian wheel from the North/East siblings. However, it never states the action verb (render/produce an image) and relies on the title and endpoint to convey that this is a rendering tool, so it stops short of a fully self-contained purpose statement.

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 when-to-use guidance and no mention of the alternatives, despite astroway_render_wheel_vedic_north and astroway_render_wheel_vedic_east being direct siblings that an agent must choose between. The layout sentence implies a regional-style choice but never says 'use this when the user follows the South Indian convention' or how to pick when the user doesn't specify.

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