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 operational context the annotations do not carry: the POST endpoint and the cost of 10 credits (Tier 1). It says nothing about response shape or any prerequisite beyond the four required fields, but with annotations doing the safety work a 3 is warranted.

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 bracket format is tidy and front-loads the formula, group, endpoint, requirements and cost with zero filler. However the lead line is cryptic notation rather than an informative opening, and the brevity reflects under-specification rather than disciplined conciseness.

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, but the description still falls short for a 16-parameter cosmobiology computation. It gives no definition of what a Witte planetary picture is, no default assumptions (e.g. which zodiac or house system applies, forcing reliance on schema defaults like houseSystem=P), and no disambiguation from the many sibling tools, leaving an agent unable to call it confidently beyond the four required fields.

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 only 31% across 16 parameters, so the description is expected to compensate and does not. It merely repeats the four required fields that are already declared in the schema; undocumented parameters such as withTnp, cosmogram, zodiacType and houseSystem receive no explanation here, and the Witte-specific options are not tied to the A+B−C=D formula.

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 resource (Witte planetary pictures) and gives the formula pattern A+B−C=D, but never states what the tool actually produces (planetary picture list? sum/difference axes?). It is a domain label rather than a verb+resource statement, and it does nothing to separate itself from close siblings like astroway_cosmobiology_midpoint_pictures or astroway_cosmobiology_cosmogram.

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 or when-not-to-use guidance at all. With eight sibling cosmobiology tools in the same group (midpoint_pictures, dial_90, sensitive_points, lefeldt_extensions), an agent has no textual basis for choosing this one over an alternative.

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