day_summary

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

With no annotations, the description carries the safety/behavior burden: it discloses the return structure and the 23:30 generation timing, which is genuinely useful behavioral context. It does not say whether the tool reads or generates, what happens for a not-yet-generated day, or any access constraints, so gaps remain.

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?

Two compact sentences, front-loaded with the purpose and contents before the timing caveat; there is no filler. Slightly dense but every clause carries information.

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 the description needn't document return values, and it correctly focuses on content scope and the 23:30 timing. Still, it omits the `day` parameter's semantics and the behavior when a summary is unavailable, leaving meaningful holes for a one-param retrieval tool.

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 0%, so the description must explain the single `day` parameter — its accepted format, valid values, and how the default 'yesterday' behaves. The description never mentions the parameter at all, so an agent must guess the date format from the schema's bare string type.

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 the resource (a single day's summary) and enumerates its concrete contents (one-line overview, morning/afternoon/evening activities, todos, commitments, risks), which makes the tool's output distinguishable from siblings like `insights` or `todos`. The retrieval verb is only implied, and no sibling is named as an alternative, so it falls short of a 5.

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 provides one useful temporal constraint — today's summary is auto-generated only after 23:30 — which tells the agent when the tool is meaningful. However, it never states when to prefer this over siblings such as `insights` or `search`, nor what to expect if the summary does not yet exist, leaving usage largely inferred.

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