meal_log_day_total

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

Annotations already declare readOnlyHint=true, so the safety profile is covered; the description adds real behavioral context by disclosing that entries logged without nutrients are counted separately and excluded from totals. It also clarifies the UTC-day vs local-log boundary, though it does not describe the shape of the returned totals.

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?

Three short sentences, front-loaded with the core computation, then the exclusion rule, then the optional parameter. No filler or 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?

For a one-optional-parameter read-only aggregate with annotations covering safety, the description supplies what matters: scope, exclusion rule, and default date. The only gap is that the returned nutrient fields are not characterized, which is minor since no output schema exists.

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%, and the single optional date parameter is fully documented in the schema. The description restates the YYYY-MM-DD format and today-UTC default without adding meaningful semantics beyond that baseline.

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 names a specific verb (sum) and resource (energy and key nutrients for one UTC day of the local meal log), making the computation clear. It does not explicitly distinguish itself from siblings such as meal_log_list, which returns entries rather than aggregates, so sibling differentiation is only implied.

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?

Usage is implied by 'one UTC day in the local meal log' and by the note that nutrient-less entries are excluded from totals, which hints at when totals differ from entry counts. There is no explicit when-to-use or when-not-to-use guidance and no named alternative tool for other aggregations.

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