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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so safety needs no restating. The description adds genuine behavioral context beyond them: the result includes national defaults that apply only while the household has no rules of its own, which tells the agent the response is a fallback-aware view rather than raw stored settings.

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?

One sentence, front-loaded with the primary resource and followed immediately by the fallback qualifier. No filler, no restatement of the title.

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 no output schema, the description covers both what is returned and the important household-vs-default condition. The only gap is that "meal rules" is left abstract despite roughly seven upsert_*_rule siblings implying distinct rule categories; naming those categories would fully close it.

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, so there is nothing for the description to disambiguate and the baseline applies. The single sentence is entirely non-parameter content and correctly spends its words on scope instead.

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?

"Read the household's meal rules" gives a specific verb plus resource, and the second clause clarifies the read includes national defaults. It is clearly a read operation, distinguishing it from the delete_rule and upsert_*_rule siblings, though it never explicitly names those siblings or clarifies the scope of "rules" (frequency, price class, cooking time, etc.).

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?

Usage is implied by the verb: an agent reads this to learn the household's active rule set. There is no explicit when-not guidance and no routing to alternatives such as the many upsert_*_rule tools for modification or delete_rule for removal, so the agent must infer the read-vs-write split.

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