add_family

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

Annotations cover the safety profile (readOnlyHint=false, destructiveHint=false, idempotentHint=false), so the bar is lower. The description still adds genuine behavioral context the annotations cannot convey: the automatic bidirectional linking of family/parent-family lists, the existence prerequisite, and the expectation that the marriage event be cited.

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?

Four sentences, front-loaded with the core action and then the prerequisite, side effect, and citation advice in descending priority. Slightly more text than strictly needed, but each sentence carries distinct information.

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 6-parameter creation tool with no output schema, the description covers the key gaps: prerequisites, automatic linkage, and citation expectations. It does not say what the return value contains or how missing father/mother are handled, but nothing critical to correct invocation is absent.

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 every parameter (father, mother, children, marriage, relationship, require_citation) is already documented in the schema, including the CitationInput precedence rules. The description's 'optional cited marriage' and 'cite to a marriage record where possible' add only marginal guidance beyond that, so baseline 3 applies.

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+resource ('Create a family linking parents and children') and immediately scopes it with the optional marriage event. An agent can distinguish this from add_person and add_child_to_family without opening any schema.

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?

Gives a clear prerequisite ('All members must already exist — create them first with add_person') and tells the agent not to also update individuals separately, which is a real when-to-use cue. It stops short of naming sibling alternatives like add_child_to_family or add_event_to_family explicitly.

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