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

Annotations already declare readOnlyHint=true and idempotentHint=true, so the description's disclosure that it 'shows' authentication details is consistent. It enriches transparency by listing the specific output fields (account, sign-in method, rate-limit tier, requests-per-minute), which is useful and goes beyond the annotation structure.

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, no wasted words. The first sentence defines functionality, the second gives usage guidance. Perfectly front-loaded and concise.

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 parameters and no output schema, the description fully covers what the tool does and what it returns. There is no missing context for an agent to successfully invoke this 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, and schema coverage is 100%. According to guidelines, baseline is 4. The description does not need to add parameter information, and it doesn't contradict anything. The value is already clear.

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 clearly states the verb 'show' and the resource 'authentication details of the MCP connection', specifying exactly what is returned (account, sign-in method, rate-limit tier, requests-per-minute). This distinguishes it from sibling tools which are all astronomical or NOAA-related, so no confusion.

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 provides three use cases: 'when the user asks which account they're connected as, why they're rate limited, or whether their sign-in worked.' While it lacks 'when not to use' or alternatives, the tool is unique enough that this is sufficient.

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