Who this credential is

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

Beyond the readOnlyHint/openWorldHint annotations, the description adds meaningful behavioral context: the call is safe to run first, reveals the credential's authorization scope, and returns the registry/base domain needed for later address construction. It also implies the call is always executable and distinguishes authentication failure modes.

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?

Two sentences with no filler: the first lists exactly what the call reports, and the second states its privileged position in a session. Important operational guidance is front-loaded.

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 parameterless, read-only identity tool, this is complete: it tells the agent what information it will get, why that information matters for building subsequent calls, and when to invoke it. No output schema exists, but the description covers the return semantics sufficiently.

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 are no parameter semantics to clarify; the baseline of 4 applies. The description instead explains the value each returned piece of identity information provides.

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 exactly what the tool reports—the acting gagarin account, the credential's capabilities, and the registry/base domain to construct addresses. It names the resource and scope, and the identity focus clearly distinguishes it from siblings such as status or platform_health.

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 gives explicit when-to-use guidance: 'Run this first in any session.' It also clarifies the diagnostic value—distinguishing 'no credential' from 'a credential that cannot deploy'—which tells an agent why this call should precede deploy and other operations.

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