get_activity_summary

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

Despite no annotations, the description covers behavior: aggregates from buffer + activity log, no side effects, and accuracy depends on buffer coverage with a suggestion to check get_buffer_status. This provides sufficient transparency.

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 description is well-structured with a concise summary followed by clearly labeled sections (USE WHEN, NOT FOR, BEHAVIOR, PARAMETERS). Every sentence adds value with no 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?

Given the tool has 1 parameter and an output schema, the description explains the return type (structured summary with per-app time, keywords, focus sessions, idle gaps) and dependencies (buffer coverage). It provides everything needed for correct invocation.

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 single parameter 'hours' is fully described: lookback window, range 1-24, default 1. Since schema coverage is 0%, the description compensates by adding semantic meaning beyond the schema's type and default.

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 it summarizes user activity over N hours, with specific verb 'summarize' and resource 'activity'. It explicitly distinguishes from sibling tools get_app_usage and get_recent_touch_events, providing purpose differentiation.

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 includes a 'USE WHEN' block with concrete user queries like 'what have I been doing' and a 'NOT FOR' block with alternatives, giving explicit guidance on appropriate usage.

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