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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is fully covered and the output schema covers the return value. The description adds only the diagnostic framing and does not disclose anything beyond that, such as what a failed check implies or any re-auth requirement.

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, both earning their place: the first states the operation, the second states the trigger. The action is front-loaded with zero 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 annotations covering safety, an output schema covering returns, and no parameters, the description supplies what remains: what is checked and when. It stops just short of telling the agent what to do with a negative result (e.g., re-authenticate), which would make it fully self-sufficient for a diagnostics 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 takes zero parameters, so the baseline is 4. The description correctly adds no parameter discussion, and there is nothing for it to document beyond what the empty schema already shows.

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: 'Check whether the current MCP session has an active Chatway connection.' The scope ('current MCP session') is precise, and among the inbox-oriented siblings this is clearly the connectivity diagnostic, so an agent can distinguish it without opening a schema.

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?

Gives an explicit trigger condition: 'Use this when Chatway inbox tools are unavailable or authentication may have expired.' That tells the agent when to reach for this over the inbox tools, though it names no alternative and gives no when-not guidance (e.g., that it should not be used to fetch data).

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