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

Annotations already declare readOnlyHint=true, but the description adds substantive context: the return is split into `untrusted` and `guide`, the guide is fixed and should be followed, and everything under `untrusted` is data written by people rather than instructions. That security-relevant framing goes well beyond what the annotations provide.

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 critical instruction ('Read-only; changes nothing. Call this first') is front-loaded, and the rest explains return shape. The long enumerated sentence about the guide is dense but earns most of its place by telling the agent what the guide contains; a small amount of list-like detail could be trimmed.

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?

There is no output schema, so the description carries the full burden of explaining return values, and it does so thoroughly: `untrusted` contents, `guide` contents, and how to treat each. An agent has enough to call this correctly without opening another tool.

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 there is no parameter semantics to document. The baseline for a parameterless tool is 4, and nothing in the description creates ambiguity about invocation.

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: read-only onboarding call that returns account identity, scopes, visible sites, and a fixed `guide` script. It is clearly distinguishable from siblings like get_account or get_profile because it is framed as the aggregate entry point for a new conversation.

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?

Explicitly says 'Call this first in every new conversation' and 'Follow `guide`', giving both the trigger and the required next action. It also names alternatives indirectly by routing the agent through the guide's recommended path and next-tool selection.

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