Add a recipe to a shopping list

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

Annotations already declare readOnlyHint=false and destructiveHint=false, but the description adds significant beneficial behavior by explaining that ingredients are merged (not replaced) and that the recipe is remembered for later removal. For a mutation that is neither destructive nor read-only, this provides precisely the behavioral nuance needed beyond annotations.

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 sentences that are front-loaded with the core action and key merging behavior, then the important pairing with the sibling tool. Every sentence adds value without redundancy.

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?

Given no output schema and the complexity of the tool (3 params, merging behavior, pairing with removal), the description is complete. It covers what happens to existing items, the recipe tracking, and the complementary tool. No gaps remain for an agent to use this correctly.

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 the baseline is 3. The description adds no additional parameter semantics beyond what is already documented in the schema. The schema does a good job explaining list_id and recipe formats, and the serving_multiplier defaults. Hence score 3 is appropriate.

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 clearly states the verb 'adds' and the resource 'a recipe's ingredients to a shopping list' including the key behavior 'merging them with what is already there'. This distinguishes it from siblings like 'remove_recipe_from_shopping_list' and 'add_shopping_list_items'.

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 description explains that the recipe is remembered on the list so that 'remove_recipe_from_shopping_list can take exactly these ingredients back off again', providing clear context for when to use the complementary tool. While it doesn't explicitly state when not to use this tool (e.g., versus adding individual items), the usage context is clear.

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