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

With no annotations, the description carries the full burden and does reasonably well: it discloses the input format, the returned fields (life path, trail, mulank, bhagyank), and a non-obvious behavioral rule that master numbers 11/22/33 are preserved rather than reduced. It does not cover error behavior for invalid dates or the shape of the 'trail' output.

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?

A single front-loaded sentence establishes input and outputs, followed by a compact example. Every clause carries information and nothing is padded.

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?

For a one-parameter, no-annotation, no-output-schema tool, the description covers the essentials: valid input shape, what is returned, and the special master-number handling. The main remaining gap is how the 'trail' is structured and what happens on out-of-range or malformed dates.

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 100% and already documents the dob format and the 1900–2100 range, so the description need not repeat it. It still adds value by supplying a concrete example payload ('{"dob":"1990-05-14"}') that makes the expected call trivially reproducible.

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 gives a specific verb ('takes a birth date') and a specific, enumerated output (life path number, trail, mulank, bhagyank), so the agent knows exactly what computation happens. It does not explicitly distinguish itself from siblings like nameNumber or loShuGrid, though the birth-date basis implicitly separates it.

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?

Usage is only implied: the agent can infer 'call this when you need a life path number from a birth date.' There is no explicit statement of when to prefer this over nameNumber or loShuGrid, nor any prerequisites or exclusions.

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