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

With no annotations, the description carries the full burden and does well: it discloses the calculation method, the returned fields, the default letters behavior, and that the result is 'a number game, not advice.' It does not mention side effects, but the operation appears to be a pure computation.

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?

The description is front-loaded with the tool's purpose and then explains the algorithm, outputs, disclaimer, and example input. It is dense but every part adds useful context. It could be slightly more structured, but there is little wasted text.

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?

Given no output schema and no annotations, the description compensates by listing the return values and explaining the scoring logic. It also provides an example input and a clear disclaimer. It is complete enough to invoke correctly, though it does not address error behavior or distinguish from the sibling tool.

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 100%, so all three parameters are already documented in the schema. The description explains the letters mode and mulank reduction, but this mostly restates or elaborates on information already present in the schema. Baseline 3 is appropriate.

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 operation: scoring a vehicle registration plate against the owner's birth number using numerology. It clearly identifies the inputs and output. However, it does not mention or distinguish the sibling tool plateTotal, so an agent must infer the difference.

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 description explains what the tool does but gives no explicit guidance about when to use it versus plateTotal or other alternatives. It does not state prerequisites, exclusions, or typical use cases beyond 'a number game, not advice.'

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