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

Annotations already declare readOnly/idempotent/non-destructive/closed-world, so safety is covered. The description adds genuine context beyond them: the 20-credit cost, the guaranteed presence of `meaning` and `meaningLocalized`, and the `translated: false` fallback when a language's strings are not yet available. That translation-fallback behavior is exactly the kind of trait an agent should know before rendering results.

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?

Front-loaded with the core value proposition (six numbers, one call), followed by cost and output-shape details. There is mild redundancy: cost appears in both the body and the trailing '[Cost: 20 credits]' tag, and the endpoint/required tags restate schema facts. Still efficient overall.

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 detailed, and the description still usefully characterizes them (each number carries meaning + localized meaning). For a read-only chart call this is near-complete; the only real gap is the unexplained reference to a 'requested language' that has no corresponding parameter.

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 60%, and the description mostly repeats what is already documented: `year` defaults to the current year, which the schema states verbatim. It alludes to a 'requested language' for `meaningLocalized`, but no language parameter exists in the schema, so that reference is ambiguous rather than clarifying. Baseline 3 for a description that does not materially extend the parameter definitions.

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?

The description states a specific verb+resource: it returns the six named core numbers (Life Path, Expression, Soul Urge, Personality, Birthday, Personal Year) in a single Vedic numerology call, and explicitly frames itself against the six single-number siblings via cost. The closing tag 'Numerology: Vedic system' also separates it from the Chaldean/Kabbalistic/Pythagorean chart variants. An agent can identify it without opening the 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?

It gives a clear selection rationale ('20 credits instead of 60 for six single calls'), which tells the agent to prefer this over repeatedly calling the single-number tools. It does not, however, explicitly name the alternative tools or state when a single-number call would be preferable. Clear context, but no explicit exclusion.

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