add_child

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

Annotations already declare readOnlyHint=false, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds the useful precondition that both the individual and family must already exist, but it does not describe side effects, duplicate handling, or what happens to existing family structure.

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 a single front-loaded sentence with no wasted words. It immediately states the action and the required entities, making it easy to scan.

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 annotations cover the safety profile. The description states the core operation and preconditions, but it does not address edge cases like adding a child who is already associated with the family or whether existing children are replaced.

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 documents file, child_id, and family_id with patterns and examples. The description adds no parameter-level detail beyond what the schema provides, fitting the baseline of 3 when structured data carries the parameter semantics.

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 states a specific verb ('Add') and resource ('an existing individual as a child of an existing family'), making the operation clear. However, it does not distinguish this tool from potentially related siblings such as set_parents or add_individual, leaving some ambiguity for an agent choosing among them.

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 implies when to use the tool (when you want to add an existing individual as a child of an existing family), but it provides no explicit when-to-use guidance, prerequisites, or alternative tools. There is no exclusion or routing advice against siblings like set_parents.

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