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 behavioral context the annotations do not: the cost (10 credits, Tier 1) and the endpoint, which matter for agent budget and routing decisions. It stops short of describing the return payload, but the 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 core purpose is front-loaded in a single efficient sentence, followed by bracketed metadata that is scannable and non-redundant. The tag block is slightly administrative but each entry (group, endpoint, required, cost) carries distinct information.

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?

With an output schema present and annotations covering the safety profile, the description's remaining burden is method and invocation context, both of which are supplied (strict Kabbalistic method, required params, cost). The one soft spot is that the role of 'date' is never stated, though it is conventional for numerology.

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 coverage is 50%: fields and precision are documented in the schema, but date and name are not. The description compensates for the name parameter by clarifying it must be the full birth name with all letters reduced, which is the semantically ambiguous one. It adds nothing for date, so the coverage gap is only partly closed.

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), a specific resource (Expression/Destiny number), and the exact computation rule (full birth name letters, all letters, reduced). It also names the system variant 'Kabbalistic (Mathers strict)', which lets an agent distinguish it from the many sibling expression tools (kabbalistic_expression, pythagorean_expression, vedic_expression, etc.) without opening their schemas.

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 named system variant implies which sibling family this belongs to, so routing is partially inferable. However, there is no explicit when-to-use statement, no guidance on choosing strict vs non-strict Kabbalistic, and no mention of prerequisites or exclusions beyond the '[Required: name, date]' tag.

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