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

Annotations only declare readOnlyHint=true, but the description goes far beyond that: it enumerates the exact failure reasons (no_credential, header_received_but_invalid_format, rejected, server-side), states that calling with no credential is a normal result not an error, and guarantees the token value is never accepted or echoed. This is rich disclosure the annotations do not carry.

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?

Front-loaded with the key instruction, and every sentence carries substantive content. It is dense and somewhat verbose in the parenthetical reason-code enumeration, but nothing is filler.

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 output schema, the description fully covers return shape (connected:true/false, scopes, expiry) and the meaning of each reason code. Nothing an agent needs to interpret or safely call the tool 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?

There are zero parameters, so the baseline is 4. The description correctly notes it is safe to call with no credential at all, but there is no parameter surface to elaborate on.

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 — verify whether the connection is actually authenticated and as what — and distinguishes it from the account.* tools whose credential-presence check it supersedes. An agent can tell exactly what this tool does and why it differs from siblings.

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 explicitly frames when to call it ('THE TOOL TO USE before assuming a connection is authenticated') and explains the trap it guards against: account.* tools register on credential presence, not validity, so their absence from the tool list is not diagnostic. The condition and the alternative are both named.

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