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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the description's job is to add context — and it does, disclosing the 50-year range cap and the 10-credit Tier 1 cost, neither of which appears in structured fields. It stops short of describing what happens on an over-range request.

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 front-loaded sentences: the operation first, the hard constraint second, with no filler. The bracketed group/cost metadata is compact and clearly segregated from the functional description.

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, and annotations carry the safety semantics. With the operation, the event definition, the range limit, and the cost all stated, an agent has everything needed 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?

Schema coverage is 50%: 'fields' and 'precision' are well documented in the schema, while the two required parameters (startYear/endYear) carry no schema description. The description partially compensates by framing them as a bounded year range with a 50-year maximum, but adds no type, format, or ordering detail beyond that.

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?

States a specific verb and resource ('Calculate Rave New Year dates') and even defines the underlying astronomical event ('exact moment Sun enters Gate 41'), which is far more than the title conveys. It does not, however, explicitly distinguish itself from related siblings such as astroway_hd_dream_rave or astroway_hd_design_date.

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?

The description bounds usage with 'for a range of years' and an explicit 'Max range: 50 years' limit, so an agent knows when the tool cannot be applied. It names no alternatives and gives no when-not guidance relative to the other Human Design siblings.

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