List GA4 accounts and properties

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, and the description reinforces this with 'Read-only.' It adds useful context beyond the annotations by stating the authentication scope ('accounts the authenticated user can see') and describing the return content (account name, display name, property ID and display name), which is valuable since no output schema is present.

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 sentences efficiently deliver purpose, usage guidance, and return fields with zero filler. The most important instruction ('Use this FIRST to discover propertyId') is front-loaded in the second sentence, and every clause earns its place.

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 simple list tool with two optional parameters and no output schema, the description covers the purpose, the discovery workflow, and the returned fields. It also confirms read-only behavior. Nothing an agent needs to call this tool correctly is missing.

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 100%, so both parameters (limit, pageToken) are fully documented in the input schema with their own descriptions. The tool description does not add parameter-specific semantics, which is acceptable given the schema already handles the heavy lifting. Baseline 3 is appropriate.

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 states a specific verb ('Lists'), resource ('every Google Analytics account ... with the properties under each'), and scopes the operation to what the authenticated user can see. It also names the primary use case (discovering propertyId), distinguishing it from sibling GA4 reporting and management 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?

It explicitly tells the agent to use this FIRST to obtain the numeric propertyId that other GA4 tools require, providing clear when-to-use context. It does not offer explicit when-not-to-use guidance or name alternatives, but the 'FIRST' instruction and relation to other tools are strong directional cues.

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