op_list_time_entry_activities

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

No annotations are provided, so the description carries full burden. It discloses the 404/empty list behavior and that activities may be mandatory, which adds useful context beyond a bare list call. However, it does not discuss other behaviors like authentication, rate limits, or response format beyond the basic list structure.

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 compact and well-structured: purpose, usage hint, error condition, and return format are each briefly covered. Every sentence earns its place without 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?

For a simple zero-parameter list tool with an output schema, the description covers the essential context: what it lists, how to use the results, and what to do if it fails. It is sufficiently 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 tool has zero parameters, so schema coverage is 100% by default. The description adds value by explaining the output elements (id, title) and how they relate to op_log_time's activity_id parameter, which is more than necessary for a parameter-less tool.

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 starts with a clear verb+resource: 'Get the list of available time tracking activities.' It explicitly distinguishes itself from siblings by focusing on activities rather than time entries or logging, and directly references its output being used by op_log_time.

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 clear context on when to use the tool: before logging time, to fetch valid activity IDs for op_log_time. Also explains the 404/empty list scenario, indicating the module is not enabled. Does not explicitly list when not to use alternatives, but the reference to op_log_time gives sufficient guidance.

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