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

Annotations already cover the safety profile (destructiveHint=false, readOnlyHint=false), but the description goes beyond them: it states nothing is notified ('reaches no one'), that the write is fully reversible in one delete_diary_item call, and that a Cotlet API key with app access is required. That is meaningful operational context the annotations do not convey.

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 and efficient, with the highest-value facts (what it does, reversibility, no confirmation) early. Sentence one and two partially restate the same purpose ('add a product or meal...' vs 'adds one product or meal...'), which is minor redundancy against otherwise tight phrasing.

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 five-parameter write with full schema coverage and no output schema, the description suffices: it covers intent, prerequisites (API key), reversibility, and confirmation behavior. Only the distinction from log_quick_entry/other logging paths is left implicit.

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 schema already documents all five parameters including units and the food_id source. The description's 'grams, milliliters or a handy measure such as a slice or a package' largely restates the unit field, adding only marginal flavor rather than new constraint semantics.

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 (add/log) and resource (product or meal into a meal on a day), and names both the source sibling (search_food) and the inverse operation (delete_diary_item). An agent can distinguish this from fitatu_search_food and fitatu_log_quick_entry without opening a 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?

Explicitly says it runs without asking first (no confirmation needed), points to search_food as the source of the ID, and names delete_diary_item as the undo path. It stops short of contrasting when to use this versus fitatu_log_quick_entry for free-text logging, so 4 rather than 5.

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