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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so safety is covered. The description adds behaviorally relevant metadata the annotations do not carry: the credit cost (100 credits, Tier 4), the POST endpoint, and the required parameter set, all of which help an agent decide whether the call is worth making.

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 core sentence is front-loaded and wastes no words, and the bracketed metadata lines are compact and skimmable. The bracketed block is somewhat boilerplate-heavy, but it does not bury the functional description.

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?

With an output schema present, return values need not be described, and the description covers scope, cost, endpoint and required input adequately for a computation tool. The remaining gap is sibling disambiguation against the other group/overlay tools, which leaves an agent to infer the boundary.

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 67% and the nested input-object schema is unusually detailed (timezone vs timezoneOffset semantics, houseSystem letter codes, whitespace/alias rejections). The description only restates that inputs is required and that the list holds 3–5 people, both already encoded in required/minItems/maxItems, so it adds little beyond 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 Penta (group) chart") plus a concrete scope constraint ("3–5 people") and what it produces ("combined BodyGraph showing group dynamics and collective conditioning"). It stops short of differentiating itself from close siblings like astroway_hd_group_overlay, which an agent could easily confuse with a group-chart tool.

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 3–5 person constraint implicitly tells the agent when this tool is applicable, but there is no explicit when-to-use guidance, no exclusions, and no routing to alternatives such as astroway_hd_group_overlay or astroway_hd_human_design_compatibility, which also handle multiple people.

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