Birthday (chaldean)

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

Annotations already declare readOnly/idempotent/non-destructive, so the bar is low, and the description adds real operational context beyond them: cost ('10 credits (Tier 1)') and the POST endpoint. It does not describe the response shape, but an output schema exists to cover that.

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?

One sentence of real description, front-loaded with the action, followed by compact bracketed metadata. No filler prose, though the repeated 'Required' line duplicates the schema's required array.

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?

A simple two-parameter calculation with an output schema, so much is already covered; the description supplies purpose, cost, and endpoint. Still missing the date input format and the purpose of the name parameter, which an agent needs to call it correctly.

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 0%, so the description must carry parameter meaning and largely doesn't. 'From the day-of-birth digit' loosely maps to date, but the required YYYY-MM-DD format from the schema pattern is never mentioned, and the role of the required 'name' field for a day-digit calculation is left unexplained.

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?

Specific verb and resource: 'Calculate the Birthday number from the day-of-birth digit', scoped to the Chaldean system. That system label implicitly separates it from the many sibling birthday variants (pythagorean_birthday, kabbalistic_birthday, vedic_birthday), though no sibling is named explicitly.

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?

No guidance on when to pick this over the other numerology birthday tools, no prerequisites, no exclusions. The only contextual line is 'Required: name, date', which restates the schema rather than advising usage.

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