slack_user_activity

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

With no annotations, the description fully discloses behavior: searches both from and to the user, optionally includes surrounding channel history, optionally expands threads, deduplicates, and returns nested replies plus a stats block. This goes beyond a simple verb phrase and provides actionable context about how the tool operates.

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: a concise opening statement, a short usage rationale, and a clear parameter list. Every sentence adds value; no fluff or repetition. It is appropriately sized for a tool with 6 optional parameters and complex behavior.

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's complexity, the description covers purpose, usage, behavior, cost, and parameters thoroughly. The output schema is present, so return values need not be described. This description is fully complete for an AI agent to select and invoke 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?

The schema has zero descriptions, so the description carries full weight. The Args section explains each of the 6 parameters with formats, defaults, and behavioral implications (e.g., 'context_window: Seconds of surrounding channel history... 0 fetches no context'). This is far richer than the bare schema and gives the agent all needed parameter semantics.

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 opens with a clear, specific verb phrase: 'Everything one person said or received in a time range, grouped by channel.' It explicitly distinguishes itself from siblings by stating 'Prefer this over assembling the same result from slack_search plus slack_channel_history plus slack_thread,' making the tool's unique role immediately obvious.

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?

Provides explicit usage guidance: 'Prefer this over...' and explains why (deduplicates across passes). Also gives a practical constraint: 'Cost scales with the number of channels the user was active in.' This helps the agent decide when this tool is the right choice.

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