retention_report

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

With no annotations provided, the description carries the full burden of disclosing behavioral traits. It only states the core computation and timezone requirement, omitting details like data aggregation, performance implications, or authorization needs. More context is needed for an agent to invoke this correctly.

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 extremely concise at two sentences. It front-loads the purpose and immediately gives a key requirement. Every word earns its place; 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 lack of output schema and moderate complexity (time series computation), the description is insufficiently complete. It does not explain the output format, how to interpret return fractions, or how date range boundaries are handled. Siblings like funnel_report likely have more structured descriptions.

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 adds the context that retention is based on 'visitors first seen in the range', which is not in the schema, providing slight extra value. However, it does not elaborate on parameter usage beyond what the schema already states.

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 computes the fraction of visitors returning on each subsequent day for those first seen in the range, effectively defining the metric and scope. However, it does not explicitly differentiate from sibling tools like funnel_report or journey_report.

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 mentions a requirement (timezone) but provides no guidance on when to use this tool versus alternatives, nor any conditions or exclusions. The agent has little context to decide between retention_report and other analytics tools.

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