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

Annotations already cover the safety profile (readOnlyHint=true, destructiveHint=false, openWorldHint=true). The description adds genuinely new behavior: when GA is not part of the connection, the tool reports that and returns a grant_url the user must open to authorize. That fallback/remediation path is not derivable from annotations or schema.

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 short sentences, front-loaded with the core action, then downstream usage, then the failure-mode behavior. Every sentence carries distinct information and there is no filler.

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?

With no parameters and no output schema, the description carries the explanation burden well: it covers what is listed, how to use the result, and the not-connected fallback including the grant_url. It does not describe the shape of a returned property record (e.g., id vs display name), which would close the remaining gap.

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 takes zero parameters, so the schema places no burden on the description. It appropriately mentions property_id as the output value to carry into downstream tools rather than as an input, which is context the schema cannot express.

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 with scope: 'Lists the Google Analytics 4 properties this Google login can read.' The scope qualifier (properties readable by this login) is more precise than the title alone, and it hints at its role relative to other GA tools, though it never names a specific sibling to differentiate against.

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?

'Use a property_id from here in the other Google Analytics tools' tells the agent this is the entry point for GA workflows, which is actionable routing guidance. It stops short of naming which sibling to use next (e.g., analytics_report vs analytics_setup) or when the tool is not needed.

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