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

Annotations already declare readOnly/idempotent/non-destructive, and the description goes well beyond them by enumerating every category of problem reported (unknown or duplicate ids, self-ancestry with cycle named, >2 biological parents, parent not older than child, couple years outside a partner's life, twins with different parents, too many generations). It also discloses the 150-person cap and the truncation behavior that names omitted people, which an agent could not infer from annotations or schema.

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 trigger condition is front-loaded, followed by input equivalence, output contents, and negative scope. The problem enumeration is long but each clause adds distinct information; a bulleted list would be more scannable, but nothing is redundant.

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?

For a validation tool with 100% schema coverage, annotations, and an output schema, the description covers trigger, alternatives, checks performed, limits, and side-effect absence. An agent has everything needed to decide to call it and to interpret the result.

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 schema already carries field-level meaning and the baseline is 3. The description adds a real semantic constraint beyond the schema: it accepts the same people/relations/household as make_genogram but explicitly excludes health or medical details, which matters because the schema permits additional properties.

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 specific verb and resource ('a family list checked before drawing a genogram') and immediately differentiates from the sibling: 'Draws nothing and makes no files' versus make_genogram, which draws. The quoted user phrasings ('check my genogram data for mistakes') anchor the intent unambiguously.

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?

It states exactly when to use it (before drawing a genogram) and implies the alternative by contrasting with make_genogram, which takes the same inputs. It also sets explicit scope boundaries: relationships only, no health or medical details, no files or drawings produced.

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