Calculate a two-person composite relationship chart.
Plan: Standard or higher · Cost: 2 credits per call.
| Name | Required | Description | Default |
|---|---|---|---|
| verbose | No | ||
| person_a_birth_datetime | Yes | ||
| person_b_birth_datetime | Yes |
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are present, so the description must carry full burden. It lacks information on side effects, data retention, or authentication needs beyond plan/credit hints.
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 description is very short (two sentences) and front-loaded with purpose. The cost/plan info is useful but could be separate. Still, it's concise.
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?
Despite having an output schema, the description neglects to explain parameters or any contextual details about composite charts. It is insufficient for a 3-parameter tool with no schema descriptions.
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?
With 0% schema coverage, the description adds no meaning to parameters (verbose, person_a_birth_datetime, person_b_birth_datetime). It fails to clarify expected formats or purpose for verbose.
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?
The description clearly states the tool calculates a two-person composite relationship chart, distinguishing it from siblings like calculate_bodygraph (individual) and calculate_penta (group).
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 mentions plan requirements and credit cost, providing context for when to use. However, it does not explicitly state when not to use or name alternatives.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.
Each tool targets a distinct type of calculation (bodygraph, composite, dreamrave, penta, transit, location search) with no overlap, making it easy for an agent to select the correct one.
Most tools follow a 'calculate_' pattern, but 'get_transit' and 'search_locations' break the pattern, introducing inconsistency. While the verbs are descriptive, the lack of uniformity may confuse agents.
With 6 tools, the server is well-scoped for a Human Design calculation API—covering all major chart types and a helper function without superfluous tools.
The tool set covers all primary Human Design calculations (individual, composite, dreamrave, penta, transit) and location lookup. Missing are tools for interpreting or persisting results, but core calculations are complete.
