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

Goes well beyond the annotations (readOnlyHint=false, destructiveHint=false): states the entry is not saved to the Own list, is undone with one call to delete_diary_item, and runs without asking first, and notes the Cotlet API key requirement. This is rich, non-obvious behavioral context.

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?

Front-loaded with the core purpose, and the safety/reversibility facts are stated efficiently. Minor redundancy in restating 'like Quick add in the app' / 'the way Quick add does' twice, which slightly dilutes it.

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 six-parameter mutation with no output schema, it covers auth, persistence, reversibility, and non-interactivity. It does not describe what the call returns (e.g., an entry identifier needed for later undo), which would be useful for chaining with delete_diary_item.

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 coverage is 100%, so all six parameters are already documented in the schema. The description adds no format or default detail beyond what the schema provides (e.g., date default, meal names), so the baseline 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?

Specific verb+resource (add calories/macros to a meal) plus a clear differentiator: 'without picking a product.' This separates it from fitatu_log_food, which requires a product, without the agent needing to open either schema.

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 concrete usage conditions ('diet catering or values copied from a label') and ties reversibility to the delete_diary_item sibling. It does not explicitly name fitatu_log_food as the alternative to avoid, so the when-not is only implied.

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