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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds genuinely useful non-schema context (cost of 10 credits, Tier 1), but says nothing about determinism, output shape, or edge cases in day-digit reduction.

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 plus two bracketed metadata tags; the purpose is front-loaded and there is no filler. The cost/group tags are compact rather than verbose, though they are structured metadata rather than explanatory prose.

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 the cost is disclosed. Still, for a 4-parameter tool with half the params undescribed and no explanation of what the Birthday number signifies or how invalid dates are handled, the definition is only minimally complete.

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 'name' and 'date' carry no descriptions. The description's phrase 'from the day-of-birth digit' loosely signals that 'date' drives the result, but it adds no format, constraint, or validity detail beyond the schema.

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 and resource ('Calculate the Birthday number') and pins the system ('Numerology: Vedic system'), which is what separates it from the many chaldean/kabbalistic/pythagorean/numks birthday siblings. It stops short of explicitly contrasting with those siblings, so it is clear but not maximally differentiated.

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: Numerology: Vedic]' tag plus the Vedic label implies this is the tool to pick when the Vedic system is wanted, which is a reasonable routing cue against the identical-suffix siblings. However, no explicit when-to-use, when-not-to-use, or named alternative is given.

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