calculate_family_constellation_matrix

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 is covered; the description adds genuinely new context: zero-auth, stateless, no PII stored, whitespace trimming of date tokens, silent dropping of over-limit or invalid entries, and a structured JSON error if fewer than one valid relative remains. That is unusually rich behavioral disclosure, though it does not describe output characteristics beyond the error case.

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?

Front-loaded with the core purpose and size constraint, then the sibling routing, then edge-case behavior. It is dense (one very long sentence with several parenthetical clauses), but nearly every clause carries actionable information; light restructuring would improve scanability.

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 not be explained, and the definition still covers the failure mode (structured JSON error), size limits, parsing quirks, and localization. For a 3-parameter, well-annotated read-only tool this leaves nothing an agent needs missing.

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 100%, so the baseline would be 3, but the description adds meaning the schema lacks: whitespace around `YYYY-MM-DD` tokens is trimmed, entries beyond 30 dates or failing ISO validation are silently dropped, and `lang` localizes all group roles and shared medicine. This clarifies real parsing semantics rather than restating field descriptions.

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') plus two named outputs (Family Constellation Matrix and 4-Element group balance) and the input scope (primary person + relatives). It also names the sibling tools that handle the other group sizes, so an agent can distinguish it without opening a schema.

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?

Gives explicit routing rules: use this for groups of 3 to 31 people, use `calculate_7_wisdoms_seed_of_life` for one person, and `calculate_3d_soul_synastry` for a pair. Both when-to-use and the alternatives are spelled out.

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