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

Beyond the readOnlyHint annotation, the description discloses important behavior: an invalid token silently degrades to anonymous rather than producing an error. This is exactly the kind of non-obvious behavioral trait an agent needs to interpret results correctly.

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 core purpose is front-loaded, and the authentication caveat is placed where it adds the most value.

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 zero-parameter, read-only identity check, the description fully covers what the tool does, when to use it, and the key failure behavior. No output schema exists, but the description sufficiently indicates what the response covers: resolved tier and limits.

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 burden. The description appropriately focuses on what the call reports rather than inputs.

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 a specific verb and resource: 'Check how this session is authenticated: resolved tier (anonymous / free / pro) and its limits.' It clearly identifies the tool as an identity/tier inspection utility and is distinguishable from siblings like dropyour_status or dropyour_logs.

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?

The description explicitly tells the agent when to call it: 'Call this after configuring an account token (dyk_...) to confirm it is recognized.' It also gives a critical usage nuance: an invalid token silently degrades to anonymous, which tells the agent what to verify.

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