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

Annotations already declare this a read-only, idempotent, non-destructive, closed-world call. The description adds genuinely useful operational context beyond that: the POST endpoint and the 10-credit Tier 1 cost, which affects whether an agent should spend a call. It says nothing about what is computed or returned, but with annotations carrying the safety profile a 3 is fair.

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 technique name is front-loaded and the bracketed metadata lines are compact and scannable. Every line carries some information, though the endpoint and required-params lines are largely restatements of already-structured data.

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, niche cosmobiology tool surrounded by near-synonym siblings, the description gives no conceptual output overview and no selection criteria. With an output schema present it need not describe return values, but the missing usage disambiguation and parameter explanation leave an agent unable to confidently choose it over dial_90 or witte_formulas.

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 bears real explanatory burden. It lists the four required fields (already in the schema's required array) but adds no meaning for ambiguous optional parameters like withTnp, cosmogram, zodiacType, houseSystem, or ayanamsaId, leaving most parameters undocumented in both places.

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 specific technique ("Lefeldt-Brummund 22.5° subdivisions") plus its family and endpoint, which is more than a tautology. But it uses unexplained jargon with no verb and no statement of what the output actually is, and it does not differentiate from several close siblings such as witte_formulas, dial_90, or midpoint_pictures.

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?

"Required: date, time, latitude, longitude" is parameter metadata, not usage guidance, and it merely repeats the schema's required list. There is no when-to-use, no when-not-to-use, and no routing to any of 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.