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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and a closed world, so safety is covered. The description adds genuinely new behavioral context: a credit cost (10 credits, Tier 1) and the group it belongs to, plus what the result contains (four cycles with age boundaries). It does not describe failure modes or credit-refund behavior, keeping it out of the top band.

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?

Front-loads the operation and system in the first sentence, then tucks group, cost, and alias into bracketed metadata lines that are short and skimmable. Slightly padded by three meta-lines for a two-parameter computation, but nothing is wasted.

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-value explanation is unnecessary, and the description still states the shape of the result (four cycles with age boundaries). The main remaining gap is that the two required inputs are undocumented in both description and schema, which matters for a name-and-date numerology calculation.

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?

Two of four parameters (name, date) carry no description in the schema, giving only 50% coverage, and the description does not compensate — it says nothing about what name means (subject's full name for letter-based numerology) or how date is interpreted. The two documented optional params (fields, precision) are compact-mode mechanics unrelated to this tool's core computation.

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 four Pinnacle cycles with their age boundaries) and names the exact system variant (Kabbalistic, Mathers strict), which is what separates it from the Chaldean, Pythagorean, Vedic, and non-strict Kabbalistic siblings. The alias note further clarifies its relationship to astroway_numerology_kabbalistic_strict_pinnacles.

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 alias note ('cursor-friendly alias for astroway_numerology_kabbalistic_strict_pinnacles') implies a routing rule — prefer this short name in cursor-style clients — but there is no explicit when-to-use, when-not-to-use, or comparison to the other pinnacle variants. Usage must be inferred from the system name alone.

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