list_account_summaries

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

With no annotations, the description carries the transparency burden. It discloses the access scope ('the service account can see'), the exact return fields (account name/id, property display name and numeric id), and its role as a discovery step. It does not mention potential pagination or rate limits, but for a simple read-only list tool this is adequate.

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?

Two concise, information-dense sentences. The first states the core function, the second details the return payload and usage guidance. No wasted words.

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's simplicity (0 params, output schema present), the description is fully complete. It covers what it returns, who can use it, and how it fits into the broader toolset.

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 a baseline of 4 is appropriate. The description adds no parameter details because none exist, and the schema already confirms the empty parameter set.

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 lists every GA4 account and its properties visible to the service account. It distinguishes itself from sibling tools by explicitly positioning it as the discovery entry point: 'Call this first to discover property ids for the other GA4 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?

Provides explicit when-to-use guidance: 'Call this first to discover property ids for the other GA4 tools.' This tells the agent this should be the initial discovery call before using the GA4 tools, effectively differentiating it from siblings.

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