get_traffic_sources

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

Annotations already declare readOnly, idempotent, openWorld, and non-destructive, so the safety profile is covered. The description adds one genuine behavioral fact — results are sorted by sessions descending — but says nothing about pagination behavior, default row limits, or how the account/property_id scope is resolved.

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?

A single front-loaded sentence with zero filler, listing the grain and sort order immediately. It is efficiently sized, though the terseness leaves no room for the usage or parameter context an agent needs.

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?

An output schema exists, so return shape needn't be explained, but for a six-parameter analytics tool with fully undocumented parameters and no sibling differentiation the description is far too thin. Missing: date format expectations, property scoping, and pagination defaults.

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 0% across six parameters: start_date, end_date, limit, offset, account, and property_id are all undocumented. The description compensates only indirectly by implying the row grain (channel, source/medium), which helps interpret limit/offset, but it never clarifies date format or the account-vs-property_id relationship.

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 names the specific breakdown produced (session channel and source/medium) and the sort order, which is more informative than the tool name alone. However, it doesn't state the verb explicitly or distinguish this report from siblings like get_summary or run_report, so an agent must infer the boundary.

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?

There is no guidance on when to use this versus run_report, get_summary, or get_top_pages, and no mention of prerequisites such as needing a property_id. The description only says what the output looks like, leaving selection entirely to inference.

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