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

Adds real behavior beyond the annotations: identical open entries are returned rather than duplicated, and staples are deliberately not persisted. That is exactly the kind of side effect an agent needs before calling a write tool. There is mild tension with idempotentHint=false, but deduplication of identical entries is not the same claim as full idempotency, so this is a nuance rather than a contradiction.

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 action and the scope, followed by dedup and exclusion rules in order of decision relevance. The enumerated borderline supplements are slightly listy but they earn their place by preventing a plausible misfile.

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 two-parameter write tool with no output schema, the description covers action, dedup return behavior, staples exclusion, and cross-product routing. Return values need not be explained, and the dedup sentence already tells the agent what to expect back.

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 both 'label' and 'detail' are already documented, including the 'never computed, only read' note on detail. The description's German phrase ('setz Hafermilch auf den Zettel') illustrates intent but adds no new semantics for the parameters themselves, so the 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 and resource ('Put a food item on the user's Joiva shopping list') and immediately scopes it to food only, explicitly excluding supplements. An agent can distinguish this from stackwell_add_shopping_item without opening either schema, because the description draws the domain line itself.

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 an explicit when-to-use rule (food goes here) and a when-not-to-use rule (supplements and health products, including named borderline cases like protein powder and MCT oil, go to Stackwell's list). The only gap is that it doesn't mention joiva_update_shopping_item or joiva_list_shopping, but the routing decision that matters is fully resolved.

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