Personal Year (pythagorean)

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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile needs no restating. The description usefully adds the cost (10 credits, Tier 1) and the endpoint, which matter for agent budgeting and debugging. It says nothing about authentication, rate limits, or how the year default is resolved beyond the schema's own note.

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 purpose sentence is front-loaded and the metadata block (group, endpoint, required, cost) is scannable rather than prose. Slight redundancy in repeating the required parameters that the schema already enforces, but nothing is bloated.

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-value explanation is correctly omitted, and annotations plus the cost line cover the operational side. What is missing is disambiguation of the two date-like inputs, which is the single thing an agent is most likely to get wrong on this call.

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 33% — only 'year' is described in the schema — so the description must carry 'name' and 'date', and it does not. Critically, it never clarifies that 'date' is the birth date while 'year' is the calendar year being read; the opening phrase "for a given calendar year" actively invites an agent to put the calendar year into 'date'. Listing the required params merely repeats 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") plus the system ("Pythagorean"), which is exactly what separates it from the Chaldean, Kabbalistic, and Vedic personal_year siblings. It adds the interpretive framing ("9-year cycle of personal evolution"), so an agent knows what the output means. It does not name any sibling explicitly, keeping it just short of a 5.

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 system label implies when to choose this over the other numerology personal_year tools, but the description never says so directly and offers no when-not guidance. There is also no hint that the optional 'year' parameter is what makes this a forecast rather than a natal calculation — that choice is left entirely to inference.

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