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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. The description adds genuinely useful context beyond that: the endpoint (POST /v1/...), the required inputs, and a cost of 10 credits (Tier 1). It does not need to describe return format since an output schema exists.

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 sentence comes first and the metadata (group, endpoint, required, cost, alias) is stacked in compact bracketed lines. Nothing is wasted, though the endpoint and alias lines are operational bookkeeping rather than selection-relevant content.

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 profile. The description covers purpose, system, required inputs and cost, which is enough to invoke the tool correctly; only the differentiator between the strict and non-strict kabbalistic variants is left implicit.

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 itself, while `name` and `date` are only constrained by pattern/length. The description repeats '[Required: name, date]', which the schema already marks as required, so it adds no meaning beyond the structured data. Baseline 3 is appropriate.

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) plus resource (four Challenge cycles), and pins the exact system: 'Numerology: Kabbalistic (Mathers strict)'. This lets an agent separate it from the chaldaic, pythagorean, vedic and non-strict kabbalistic challenge siblings without opening any schema.

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 [Group] tag and system label imply when this tool applies, but there is no explicit when-to-use statement, no exclusions, and no named alternative among the many sibling variants (e.g. kabbalistic vs kabbalistic_strict, challenge vs pinnacles). Guidance is inferable from the naming, not stated.

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