ga4_create_data_stream

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

With no annotations provided, the description carries the full behavioral burden. It does disclose one genuinely useful behavior - confirm must be true to actually create - which is a safety gate not obvious from the schema alone. However, it omits other behavior such as whether creation is reversible, error outcomes, or what the response contains, so coverage is partial.

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 efficient and front-loaded: the key behavioral fact (measurement ID minting) appears immediately, followed by a compact Args list. Each parameter line earns its place. It is slightly format-heavy with the 'Args:' block, but nothing is wasted and it reads clearly.

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 five parameters, no annotations, and the presence of an output schema (so return values need no explanation), the description covers most of what an agent needs: the confirm gate, required URI, and stream types. The undocumented property_id parameter, absent from both schema semantics and description, leaves the call incomplete in one area.

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 must compensate. It explains four of five parameters with real semantics: display_name as the GA4 UI label, default_uri as the site root URL required for web streams, stream_type's three enum values, and confirm's gating role. Only property_id is left unexplained, leaving a small gap.

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 verb and resource ('Create a data stream') and goes further to explain the concrete effect: for WEB_DATA_STREAM it mints the measurement ID (G-XXXXXXX) that a GTM tag or gtag.js points at. This is a specific, distinguishing detail that sets it apart from the sibling create/update/delete/list data stream tools.

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 arg explanations give partial usage guidance (default_uri is 'required for WEB_DATA_STREAM', stream_type lists the three valid values), which helps an agent build a correct call. However, there is no explicit when-to-use versus when-not-to-use guidance, and no alternatives are named, so the usage context is implied rather than stated.

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