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

Annotations already declare readOnlyHint/idempotentHint/destructiveHint=false, so safety is covered; the description adds genuinely useful non-schema context in the form of the 10-credit Tier 1 cost. It does not explain why 'name' is required for a calculation that is described as derived purely from the birth date, nor what the reduction rules are for master numbers.

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 purpose is front-loaded in the first sentence with no wasted prose, and the group/cost tags are short structured metadata rather than padding. Slightly more room could have been used to resolve the name/date ambiguity instead of restating the system name.

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 no explanation, and the cost is disclosed. However, the unexplained required 'name' parameter and the absent reduction/master-number rules leave an agent with gaps for a paid calculation tool.

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 50%: 'date' and 'name' carry no schema descriptions. The description partially compensates by explaining that 'date' is a birth date reduced from year/month/day, but it says nothing about why 'name' is required here, and the two compact-mode parameters are documented only in the schema.

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 ('Calculate') and resource ('Life Path number') plus the input ('from birth date, year + month + day, reduced') and names the system ('Pythagorean'), which separates it from the Chaldean/Kabbalistic/Vedic life_path siblings. It does not, however, explain what distinguishes a Life Path reading from the other Pythagorean siblings (expression, soul urge, pinnacles), leaving the differentiation mostly to the tool name.

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?

No when-to-use guidance, no prerequisites, and no mention of alternatives such as astroway_numerology_chaldean_life_path or astroway_numerology_kabbalistic_life_path. The agent must infer from the name which system to pick.

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