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

Annotations already declare readOnlyHint, idempotentHint and non-destructive behavior, and an output schema exists. The description still adds genuine value by flagging the pseudoscience nature (framing the results as entertainment rather than valid health data) and summarizing the returned shape, which goes beyond the structured metadata.

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?

Three tight sentences: purpose first, usage/disclaimer second, inputs/outputs third, with a pointer to list_bundles last. No filler, well front-loaded.

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 simple two-input read-only calculator with a full output schema, nothing an agent needs to call it correctly is missing; the pseudoscience caveat and return summary round it out.

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 both parameters are already documented with format. The description merely lists the two inputs without adding syntax or constraints, so it neither compensates for nor improves on the schema – the baseline 3 applies.

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?

States a specific verb (compute) and resource (physical/emotional/intellectual biorhythm cycles) and specifies the required inputs. It is clearly distinguishable from neighboring calculation tools like calculate_age or calculate_life_path_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?

The phrase 'Use for self-tracking enthusiasts (pseudoscience)' gives some context about the intended audience, and it points to list_bundles for related 'fun' calculators. However, it never states when-not to use this tool or names a concrete alternative, so usage is only implied.

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