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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint=false and destructiveHint=false, so safety and determinism are covered structurally. The description adds only that inputs are minimal (DOB plus optional name); it says nothing about determinism of the calculation, validation failures, or output shape beyond the attribute list.

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 compact sentences, front-loaded with the domain and computed values, with the input requirement last. Dense but no filler; every clause carries information an agent can use.

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 no output schema, the description correctly enumerates the returned values (the three numbers plus ruling planet, colour, day, friendly numbers), and it states the required input. For a two-parameter, read-only tool this is close to complete; only the exact response structure/precision is left unspecified.

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% (date documented, name undocumented), so the description must compensate, and it does: it marks name as optional and links it to Naamank (the Chaldean name number), which explains why the parameter exists. It does not add format or length guidance for name beyond what the schema already enforces.

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?

Names the domain (Vedic numerology) and enumerates exactly what is computed: Mulank, Bhagyank and Naamank, plus the derived attributes (ruling planet, lucky colour, day, friendly numbers). This is clearly distinguishable from every sibling, which are all natal-chart/muhurat/astrology tools rather than numerology.

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 supplies the input precondition ('Needs only date of birth (and optional name)'), which is useful routing information, but it never states when an agent should pick this tool over a sibling or what the tool is not for. Usage is implied by input requirements rather than stated.

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