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

Annotations already declare this a read-only, idempotent, non-destructive call, so the safety profile is covered. The description adds genuinely useful behavioral context beyond that: how the score is computed, that a field with a daily goal becomes its own row (e.g. "Food · Protein"), and that weekly/monthly/dated goals appear but are excluded from the day score.

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 what the summary contains, then scoring rules, then usage triggers. It is dense but nearly every clause carries information; the field-row explanation is the longest piece but justified by the non-obvious scoring behavior it clarifies.

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?

An output schema exists, so return formatting need not be described, yet the description goes further by explaining the semantics behind the score and row layout that a schema cannot convey. Combined with a fully documented parameter, an agent has enough to call it correctly; only explicit sibling routing 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?

Schema description coverage is 100% and the single `day` parameter is fully documented in the schema (format, timezone, default of today). The description adds nothing further about the parameter, so the baseline of 3 applies.

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+resource and details the scope: per-topic state across everything the person tracks, plus the day score. It implicitly separates itself from summarize_topic by scoping to the whole day ('across everything the person tracks'), but never names the sibling, leaving a small ambiguity risk given the near-identical name.

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 gives explicit trigger phrases for when to use it: "how was my day" or "how am I doing today". There is no stated when-not or named alternative, so it stops short of full routing guidance.

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