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

Annotations only provide generic flags (readOnly, idempotent, destructive). The description adds meaningful behavioral detail: the resource is persistent, validation rejects with JSON-path errors, and the payload should be fixed in one pass. It also discloses that the tool returns the household id, which is not present in the annotations or output 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?

Two dense sentences with no filler: the core action is front-loaded, then validation behavior is stated, then the return value and downstream usage are explained. Every clause contributes useful information for an agent deciding whether and how to call this tool.

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 three-parameter tool with a nested household object and no output schema, the description compensates well by referencing the full schema spec, summarizing its contents, explaining validation error behavior, and stating the returned id for use with sibling tools. An agent has enough information to construct and correct a valid household payload.

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?

Input schema coverage is 100%, so the schema already documents the parameters. The description adds value by enumerating what the household-schema document contains (members, accounts by tax wrapper, liabilities, income/expense streams) and pointing to the spec, but it does not add much beyond that for label or api_key.

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 and resource: 'Create a persistent household resource from a household-schema document.' It clearly distinguishes this from sibling tools like get_household, replace_household, and project_household by identifying creation as the action and naming the returned id for use with those downstream operations.

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 creation context is clear: this tool is for creating a new persistent household from a schema document, not for reading or updating an existing one. It also explains that the returned household id is intended for use with get/replace/project_household, giving lifecycle context, though it does not explicitly state 'use replace_household instead for updates.'

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