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

Annotations already mark the operation as read-only and non-destructive, and the description does not contradict this. It adds valuable behavior context by explaining the Penta's fixed six-channel structure and exactly what gets reported: filled gates, defined channel strengths, upper versus lower generative channels, the 2/14 material core, and functional gaps.

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 front-loaded with the action and stays compact despite explaining a rich domain. The member size constraint appears in both the description and the schema, slight redundancy, but the output-oriented sentence 'It reports which of the twelve Penta gates...' earns its place because there is no output schema.

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 no output schema, the description carries the burden of describing what the caller will receive, and it does so concretely: gates filled, channel Strengths, upper/lower channels, 2/14 core, and functional gaps. Together with the detailed input schema and read-only annotations, this is enough for an agent to invoke 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 100%, so the input schema already defines 'members', 'lang', and 'compact' well. The description mainly restates the member size rule already present in the schema's minItems/maxItems, so it does not add new parameter semantics 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?

The description opens with a direct action and resource: 'Calculate the Human Design Penta (BG5, Base Group 5) for a small group of three to five people.' It enumerates the output dimensions, so an agent can tell this is a group Penta computation rather than a personal chart or connection 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 description explicitly narrows valid call conditions: 'Below three people no Penta forms and above five a second Penta emerges, so the group size must be three to five.' It does not explicitly name an alternative sibling tool for other group sizes, so it stops short of a full 5.

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