get_new_users_by_source

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

No annotations are provided, so the description carries full burden. It only implies a read operation but lacks details on data aggregation, return format, time periods, or any constraints. Behavioral traits like whether results are sorted or limited are omitted.

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 concise at one sentence and front-loads the purpose. However, it lacks any structure (e.g., separate sections for usage or output), which could improve readability and guidance.

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 large number of sibling tools (30+) and the existence of an output schema, the description is too minimal. It does not explain how the output relates to new user acquisition or provide context to differentiate from similar source reports. The schema covers parameters, but the description should offer more usage context.

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 already adequately describes all three parameters (counter_id, date_from, date_to) with 100% coverage. The description adds no additional meaning beyond the schema, so baseline score of 3 is appropriate.

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 identifies effective traffic sources for new users. It uses a specific verb and resource, and distinguishes from many sibling reports focused on other metrics (e.g., conversion rate, sources summary), though explicit differentiation is missing.

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?

No guidance is provided on when to use this tool versus the many sibling tools (e.g., get_traffic_sources_types or sources_summary). There are no conditions, prerequisites, or exclusions mentioned.

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