daily_digest

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

With no annotations, the description carries the full behavioral burden. It discloses the output contents in detail, including the 'three shortest prompts as samples,' and clarifies date semantics: YYYY-MM-DD in the local timezone, defaulting to today. It does not mention auth, rate limits, or explicitly state read-only behavior, but for a read-only digest tool these are minor omissions.

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 sentences deliver output composition, date semantics, and routing guidance with no filler. Every clause adds information the agent needs.

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?

The tool is simple—one optional parameter—and the description fully explains that parameter and the return contents. It also names the sibling tool for multi-day queries, making the description self-sufficient for selecting and invoking the tool correctly.

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%: the schema only provides a nullable 'date' property with no description. The tool description compensates by specifying the format (YYYY-MM-DD), timezone context, and default-to-today behavior. It does not discuss valid date ranges or how past/future dates behave, but for a single optional parameter the guidance is substantially helpful.

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 deliverable—a per-day digest—and enumerates its components (first/last activity, active_minutes, sessions, prompt samples, context_switches, top_terms), making the scope concrete. It also explicitly distinguishes itself from time_summary, which covers multi-day summaries. An agent can clearly tell what this tool returns.

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 use cases: 'what did I do today?' and end-of-day reviews. It also names the alternative tool, time_summary, and the condition that selects it ('anything spanning several days'), providing a clear when-to-use vs. when-not-to-use boundary.

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