Aspect Grid (SVG)

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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered. The description adds useful behavioral context about the output layout (triangular, cells with glyph and orb). It omits, however, that the response format defaults to json rather than svg despite the 'SVG' title, and that supplying a precomputed chart costs 1 credit instead of 10.

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 short sentences that lead with the shape of the output and then the layout convention; nothing is padded. The metadata block (group, endpoint, cost) is boilerplate, and the description is arguably too terse rather than too long given the tool's branching input.

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 described, and annotations cover safety. But for a tool whose input schema branches into two very different modes with a 10x cost difference and whose format option defaults to json, the description is under-informed about how to invoke it correctly.

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?

The tool has one top-level parameter, body, with 0% description coverage and no explanation in the description of the anyOf branch. The description never tells the agent that body accepts either birth data or a chart you already hold, even though the schema's nested descriptions make the chart path 1 credit versus 10. The rich nested schema text partly compensates, but the description itself contributes nothing about parameters.

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 a concrete artifact (a triangular aspect matrix where rows and columns are planets and each cell holds an aspect glyph plus orb) and characterizes it as the standard textbook layout. That is specific enough to tell an agent this produces an aspect-grid visual rather than a wheel or a data table. It does not, however, differentiate itself from siblings such as astroway_relational_synastry_aspect_grid or astroway_aspects_aspect_bar, which an agent could easily confuse it with.

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 guidance on when to choose this over the other render_* tools or over the textual aspect tools. It also never mentions the two mutually exclusive input modes in the schema (birth data vs a precomputed chart), which is the single decision an agent must make before calling, nor the cost difference that follows from it.

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