ga4_screen_views

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

With no annotations, the description carries the full burden; it does add real value by naming prerequisites (Data API enabled on the quota project, Viewer role on the GA4 property) and by promising that access errors explain the fix. It omits behavioral traits an agent needs before calling: result sort order, what the default limit of 50 means for truncation, and the shape of the response.

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?

Purpose is correctly front-loaded and the sentences are short, but the requirement clause is crammed and switches to Spanish mid-English ('Lector (Viewer) en la propiedad de GA4'), which is jarring for an English description and slightly obscures the permission requirement.

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?

There is no output schema, so the description is the only place to learn what a result row looks like, and it gives only the metric names without ordering, row shape, or truncation behavior. It is adequate for calling the tool, but not complete for a report tool with five parameters and no structured return documentation.

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 coverage is 80%, so the baseline is 3. The description restates the 'contains' filter behavior, which the schema already documents, and adds nothing about 'limit' truncation, the relative date syntax, or how 'property' resolves to the default property.

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 specific resource (app screens / web pages) and the exact metrics returned (views, users, engagement time), which separates it from event-oriented siblings like ga4_top_events. It never names a competing sibling such as ga4_run_report, so the differentiation is implicit rather than explicit.

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 'contains' sentence makes the optional filtering use case clear, and the closing line routes access failures to ga4_check_access. However, there is no guidance on when to prefer this over ga4_run_report or ga4_realtime_report, and no statement of when not to use it.

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