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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and a closed world, so the safety profile is covered. The description does add useful non-obvious context: this costs 10 credits (Tier 1), which matters for planning. It says nothing about whether results are cached or how the year interacts with the supplied date.

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 tight sentences with the calculation front-loaded, followed by compact metadata tags. No filler or repetition of the tool name, though the bracket tags carry little descriptive value.

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 no explanation, and the cost tag supports planning. However, for a 5-parameter tool with 40% schema coverage and many confusingly similar siblings, the definition omits both parameter meaning and tool-selection guidance.

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 only 40% and the description adds nothing about parameters. It never explains why a 'name' is required alongside a date for a Chaldean personal-year calculation, nor does it disambiguate the 'year' parameter from the date's own year. The compact-mode params (fields, precision) are left entirely to 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?

States a specific verb and resource ('Calculate the Personal Year number for a given calendar year') and names the system ('Chaldean'), which separates it from the Kabbalistic/Pythagorean/Vedic siblings. The added gloss about the 9-year cycle clarifies what the number represents, though it never explicitly contrasts against the near-identical sibling tools.

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 gives no when-to-use guidance, no prerequisites, and no routing to alternatives, despite the sibling list containing ~8 other personal-year tools across systems. Only the group/cost tags provide framing.

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