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

Annotations already mark the tool as non-read-only, idempotent, and non-destructive; the description adds concrete behavior beyond them: repeated values are safe, revision conflicts indicate concurrent changes, and a linked Chop It account is required. It also clarifies that only purchase quantities are affected.

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 description is front-loaded with purpose and examples, then moves to parameters, behavioral guarantees, conflict handling, and prerequisites. Every sentence carries operational information, and there is no redundant filler.

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 the mutation semantics, the presence of annotations, and an output schema, the description covers what an agent needs: scope, prerequisite auth, idempotency, conflict handling, and parameter interpretation. No material invocation detail is missing.

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?

With only 33% schema description coverage, the description compensates by explaining all three required parameters at a useful level: shoppingListId, expectedRevision, and changes keyed by line ID with excluded or coveredQuantity. It also explains the meaning of a revision conflict, which the schema does not describe.

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: ticking off, un-ticking, or partially covering shopping-list lines, with concrete examples. It clearly distinguishes the tool from retrieval via get_shopping_list and from recipe/pantry mutation by saying recipes and pantry are untouched.

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 explains the required data source for IDs, the idempotent repeat case, the revision-conflict recovery path through get_shopping_list, and the linked-account prerequisite. It also scopes the tool to shopping-list quantities only, making clear it is not for recipes or pantry changes.

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