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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, so the safety profile is covered. The description goes beyond them by disclosing the domain consequences of membership (shared pantry, shared cooking diary, shared-marked cookbooks, members' allergens/dislikes applying household-wide) and what in_household=false means. It does not describe caching, privacy scoping, or failure modes, but for a zero-argument read the added context is substantive.

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 identity of the tool is front-loaded in the first sentence and the routing hint is placed at the end where it belongs. The middle sentence about shared pantry, diary and allergens is long and reads more like product documentation than tool guidance, though it does earn its place by explaining why household membership matters to nearby tools.

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 zero-parameter, read-only tool with an output schema, the description supplies everything an agent needs: what is returned, how to read in_household, where to go next, and example intents. Return-value detail is correctly left to the output schema.

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?

The tool takes zero parameters, which is the baseline-4 case. The description adds a small amount of interpretive value by explaining that in_household is a signal to check rather than an input, but since it is a response field and an output schema exists, no further parameter explanation is required.

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 first sentence gives a specific verb and resource ("Read the user's household: its name and who is in it") plus the exact shape of the returned identity data. It is clearly distinguishable from write-side siblings like update_household, invite_to_household and leave_household, which the description implicitly frames as the alternative paths.

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 names a concrete alternative with the condition that selects it: when in_household=false, "invite_to_household starts one." The closing phrases ("who's in my household", "is my partner connected") give real triggering utterances. It stops short of stating explicit exclusions, e.g. that changing the household requires update_household rather than this tool.

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