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

Annotations already declare readOnly, idempotent, open-world and non-destructive, so the safety profile is covered elsewhere. The description adds no behavioral context: it doesn't say how tenancy is determined (DNS/TXT verification records, MX), how confident or stale the signal is, or what a 'clear' result actually implies.

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?

One sentence, front-loaded, with no filler and the two possible outcomes stated together. It is arguably slightly under-specified rather than over-long, but nothing is wasted.

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 one-parameter read-only check this is close to sufficient, but with no output schema the description should hint at the return shape (boolean? status string? reason?) and what evidence backs an 'attached' verdict. Those gaps leave the agent unsure how to interpret results.

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?

There is a single parameter and the schema documents it fully (100% coverage, with an example), so the schema carries the burden. The description adds no format constraints beyond the schema, which is the expected baseline here.

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 a specific question ('is this domain already attached to a Google Workspace account, or clear for a fresh tenant') with an explicit verb-and-resource framing. No sibling tool covers Google tenancy, and the outcome ('attached' vs 'clear') is immediately actionable.

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?

Usage is only implied: an agent can infer this is a pre-provisioning check, but the description never states when to call it versus adjacent checks like check_dns, lookup_mx, or check_deliverability, nor any preconditions (e.g., domain must be a registered root domain).

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