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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. The description goes beyond that by disclosing what the response contains — time zone, currency, retention, conversion setup, and data-freshness signals (sessions yesterday and 7-day) — and by flagging it as the entry point for analytics work.

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 core purpose and the return contents are front-loaded in the first sentence, with the actionable 'call this first' instruction trailing. The enumeration of health-check fields is dense but earns its place given there is no output schema.

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 full burden of explaining what comes back, and it does so thoroughly — field list plus data-freshness indicators. Nothing an agent needs in order to invoke this 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?

The tool takes zero parameters, so there is nothing for the description to disambiguate; the baseline of 4 applies.

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 names the specific resource (Google Analytics 4 properties the user selected for AskYourStack) and enumerates what each entry contains, so an agent knows this is a discovery/list tool rather than a report. It is clear and concrete, though it does not explicitly contrast itself with its closest sibling gsc_properties or 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?

'Call this first for analytics work' gives a clear sequencing cue that tells the agent when to reach for this tool. It stops short of naming alternatives (ga4_overview, ga4_report, ga4_realtime) or stating when NOT to use it, so the routing is implied rather than spelled out.

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