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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is fully covered without the description. The description does add non-schema context: the 10-credit Tier 1 cost and the alias relationship to the canonical tool. It says nothing about determinism, computation time, or what a Personal Year value represents.

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?

Tight and front-loaded: the core purpose leads, followed by compact metadata tags and a one-line alias note. The bracketed group/cost lines are structured metadata rather than filler, and no sentence 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 values need not be described, and the tool is computationally simple. However, three required parameters remain undocumented in both schema and description, and the phonetic-name requirement is only implied by the system label rather than stated – a notable gap for an input-sensitive 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?

Schema description coverage is only 40% – `fields` and `precision` are documented, but `name`, `date`, and `year` carry no descriptions. The description supplies nothing for those three required parameters beyond the phrase 'for a given calendar year', leaving the agent to guess that `name` is the subject's name in original spelling (critical for a phonetic system) and that `date` is a birth date.

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 the Personal Year number for a given calendar year') and pins the system to 'Kabbalistic (phonetic)', which meaningfully separates it from the strict-Kabbalistic and Pythagorean/Chaldean/Vedic personal-year siblings. It stops short of naming an alternative tool explicitly, so differentiation rests on the group tag rather than a direct sibling reference.

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 this over astroway_numks_personal_year, astroway_nump_personal_year, or the canonical astroway_numerology_kabbalistic_personal_year. The only routing-adjacent content is the alias note and cost tag, neither of which tells the agent when this variant applies.

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