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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and closed-world, so the safety profile is covered. The description adds genuinely useful non-annotation context — the cost (10 credits, Tier 1) and the Cosmobiology/Hamburg School grouping — but says nothing about output shape or behavioral limits.

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?

The text is tightly front-loaded: the substantive content (the angles) leads, followed by two compact bracketed tags. Nothing is wasted, though the extreme brevity is under-specification rather than true economy.

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?

For a 16-parameter computation tool with low schema coverage, the description is far too thin. The output schema exists so return values needn't be explained, but the description still omits what the grid represents, how to interpret the angles, and any parameter guidance for a complex chart-calculation tool.

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?

With 16 parameters and only 31% schema description coverage, the description carries a heavy compensation burden but adds nothing about parameters — it only lists aspect angles. Undocumented params such as city, date, name, withTnp, cosmogram, zodiacType and houseSystem are left entirely to the bare schema, so this falls below the baseline.

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 lists the specific aspect angles (22.5°/45°/67.5°/90°/135°), which conveys the domain content, but supplies no verb and never states that it computes an aspect grid. It also does nothing to distinguish this from sibling cosmobiology tools like dial_90 or midpoint_pictures, so an agent must infer the operation.

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, no prerequisites, and no mention of alternative tools. The [Group] and [Cost] tags give classification and pricing context but no indication of when this tool should be selected over the many sibling cosmobiology tools.

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