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

Annotations already declare readOnly, idempotent and non-destructive, so much of the safety profile is covered. The description adds the useful cost signal (10 credits, Tier 1), but says nothing about determinism or what the calculation returns beyond the number.

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?

One front-loaded sentence stating the operation and input, followed by compact group/cost metadata. Nothing is padded or redundant.

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. However, with 50% schema coverage and an unexplained required `date`, plus no routing guidance among ~10 near-identical siblings, the definition is only minimally sufficient for correct invocation.

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, while `date` and `name` are bare. The description helps by specifying the name must be the 'full birth name', but it never explains why a required `date` matters for a vowel-derived number, leaving a real 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?

States a specific verb and resource ('Calculate the Soul Urge number') plus the input it derives from ('the vowels of the full birth name') and the system ('Vedic'). The 'Vedic' label does differentiate it from the Chaldean/Pythagorean/Kabbalistic Soul Urge siblings, though it doesn't explain how the systems differ.

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 pick this over the many sibling Soul Urge tools (chaldean, kabbalistic, pythagorean, strict, numks) — only an implicit system-tag. No prerequisites, cost trade-offs, or alternatives are named.

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