list_account_summaries

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

No annotations are provided, so the description carries the full burden. It discloses the scope ('the service account can see') and the output structure (account name/id, property display name and numeric id), which is more than the tool name alone. However, it does not mention potential limitations like pagination or rate limits for listing all data, which keeps it from a perfect score.

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?

Three concise sentences each serve a distinct purpose: action, return value, and usage timing. No words are wasted, and the most important information is front-loaded in the first sentence.

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 the tool has no parameters and an output schema is present, the description fully covers what the tool does, what it returns, and when to call it. It is a complete and self-contained description for this simple discovery tool, leaving no significant gaps in understanding.

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?

The tool has zero parameters, so by the scoring rule the baseline is 4. The description clarifies that it takes no input and simply lists everything visible to the service account, which fully compensates for the empty schema.

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 the tool's function with a specific verb ('List every GA4 account and its properties the service account can see') and distinguishes it from siblings by positioning it as the first-step discovery tool. It also specifies the return content (account name/id, property display name and numeric id), leaving no ambiguity about what the tool does.

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 explicitly instructs 'Call this first to discover property ids for the other tools,' providing clear when-to-use guidance and positioning it as the prerequisite for all other GA4 tools. This makes the tool's role in the workflow unmistakable.

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