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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and openWorldHint=false, so the safety profile is covered structurally. The description adds genuinely useful behavioral context — the cost (10 credits, Tier 1) and the Cosmobiology/Hamburg School grouping — but says nothing about output shape or computation specifics beyond the modulus label.

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?

One sentence plus two bracketed metadata tags — no padding and the core statement is front-loaded. It is efficient, though the extreme brevity reflects under-specification rather than disciplined editing.

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 tool sitting among roughly ten cosmobiology siblings, the description omits what distinguishes the 90° dial, which parameters matter, and how results relate to the cosmogram tool. The output schema covers return values, but the selection and invocation context an agent needs is largely absent.

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, several inputs (houseSystem codes, zodiacType, cosmogram, withTnp, name, city) are undocumented in both places. The description contributes zero parameter meaning — it never mentions date, time, coordinates, ayanamsa, or any of the dial-specific flags, so it fails to compensate for the coverage 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 phrase 'All chart points in 90° cardinal modulus' names the resource (chart points) and the transformation (90° modulus), which is meaningful to a domain user. However, it supplies no verb and no differentiation from close siblings like astroway_cosmobiology_cosmogram, astroway_cosmobiology_eight_harmonic_aspects, or astroway_cosmobiology_midpoint_pictures, so an agent cannot tell which cosmobiology output this produces.

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 the 90° dial over the cosmogram, midpoint pictures, or sensitive points siblings, and no statement of prerequisites or exclusions. The only framing is the group tag, which categorizes but does not instruct.

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