run_report

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safe-read profile is covered. The description adds practical defaults (limit 25, order_desc True) and date-format flexibility, but says nothing about GA4 quota/rate limits or auth requirements, which is the kind of behavioral context that would add real value here.

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 one-line purpose is front-loaded and the args block is organized per parameter with examples, so it is easy to scan. The two documentation URLs are useful rather than filler, though the block is slightly long.

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 flexible 8-parameter report tool with an output schema, the description covers inputs well and even names the return shape (dimensions, metrics, date range, row_count, rows), which the output schema already carries. The main gap is the absence of routing guidance against its many specialized siblings.

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%, so the description carries the full burden, and it does so thoroughly: property_id format ('properties/123456789'), metrics/dimensions examples plus schema catalog links, accepted date_start/date_end formats ('YYYY-MM-DD', 'today', 'NdaysAgo'), limit default, and ordering semantics. All eight parameters are meaningfully documented.

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?

States a clear verb+resource ('Run a flexible GA4 report') and the word 'flexible' implies a general-purpose query tool, which distinguishes it in spirit from the preset siblings (top_pages, events_summary, traffic_sources). However, it never names or contrasts any sibling, so the differentiation is left to inference.

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 explicit when-to-use or when-not-to-use guidance. It does not tell the agent when to reach for run_report versus the many specialized siblings (run_realtime_report, conversions_summary, web_vitals_summary) or versus list_properties/get_property. The reader must infer usage entirely.

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