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 bar is lower. The description usefully adds pricing and tier ('10 credits (Tier 1)'), which is real context the annotations don't carry, but it never explains why a required 'name' parameter exists for a calculation it says is derived purely from birth date. No contradiction with annotations.

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 short sentences, front-loaded with the calculation and the system, followed by compact bracketed metadata for group and cost. No filler or repetition; the metadata lines are the only slightly mechanical element.

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 and the annotations are rich, so return-value and safety details are covered elsewhere. Still missing: the strict-vs-non-strict distinction against the closest sibling and any rationale for the required name input, both of which an agent needs to pick and call this tool confidently.

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 50%: 'fields' and 'precision' are documented in the schema, while 'date' and 'name' are bare. The description clarifies date semantics ('year + month + day, reduced') but the required 'name' parameter — genuinely non-obvious for a Life Path number — is left completely unexplained, which is the biggest semantic gap.

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?

Names a specific verb and resource ('Calculate the Life Path number from birth date') and pins the exact system variant ('Kabbalistic (Mathers strict)'), which is what separates it from the many sibling life_path tools across Pythagoreans, Chaldean, Vedic and plain Kabbalistic. It stops short of explaining what 'strict' changes versus astroway_numerology_kabbalistic_life_path, so the sibling differentiation is named but not justified.

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?

System and reduction method are stated, which implies when this variant is appropriate, but there is no explicit when-to-use/when-not guidance and no mention of the near-identical non-strict sibling. The agent must infer the selection criteria from the group label.

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