time_report

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

With no annotations, the description carries the transparency burden. It discloses the return format ('overall totals plus per-DAY/WEEK/MONTH buckets') and implies read-only behavior via 'Returns', but it does not describe filtering behavior, timezone handling, or potential edge cases. It adds some value beyond the schema's parameter descriptions.

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 a single, compact sentence that is front-loaded with the core purpose and output summary. Every phrase earns its place, with no fluff or repetition.

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 absence of an output schema and annotations, the description gives a clear high-level picture but omits details like filtering options (tags, type_ids) and period alternatives. However, since the input schema has exhaustive descriptions for all 8 parameters, the description doesn't need to list them. It is complete for the tool's primary role as a summary report.

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 description coverage is 100%, so baseline is 3. The description does not add significant parameter semantics beyond the schema; it reiterates the grouping concept ('per-DAY/WEEK/MONTH') which is already in the group_by enum description. It provides no new details on format or relationships.

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 the tool's function: 'Aggregated time statistics per activity type for a date range' and specifies the output structure ('overall totals plus per-DAY/WEEK/MONTH buckets'). This distinguishes it from sibling tools like list_intervals or start_activity, which handle raw data or actions.

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 implies usage for getting summaries vs raw intervals ('Aggregated' vs list_intervals), but it does not explicitly state when to use this tool over alternatives or mention any exclusions or prerequisites. No direct comparison to siblings is provided.

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