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

The description goes beyond the readOnlyHint annotation by adding a detailed safety warning that calorie/macro values are estimates and not safe for medical decisions. This is valuable behavioral context that annotations alone do not provide.

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 first sentence is concise and informative. The safety warning is long and slightly repetitive, but each sentence reinforces an important limitation, so the length is justified though it could be tightened.

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 simple read operation with two parameters and no output schema, the description sufficiently explains the return concept (per-day totals) and safety context. It does not explain behavior for empty ranges or timezone handling, but these are not critical gaps.

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?

The input schema already documents both parameters (start and end) with clear format descriptions and inclusive semantics. The description's mention of 'date range' adds no new parameter-level detail, so baseline 3 is appropriate given 100% schema coverage.

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 tool reads 'the user's diary across a date range' and reports 'per-day calorie/macro totals', specifying both the resource (diary) and scope (date range). This distinguishes it from sibling tools like get_day, which presumably targets a single day.

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 implies usage for date-range queries but never explicitly mentions alternatives or when not to use it. Sibling get_day exists but is not referenced, leaving the agent to infer that get_range is for multi-day requests.

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