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

Annotations already declare readOnlyHint=true, and the description adds value by listing the exact data returned (email, monitor counts/limits, plan limits) and the intended use case for API key verification. This goes beyond the bare read-only flag, though it doesn't cover error cases or rate limits.

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 short sentences. The first sentence immediately answers 'who am I' with concrete outputs, and the second gives a practical use case. No filler or redundancy.

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 stateless read-only call with no parameters and no output schema, the description fully covers what an agent needs: what it does, what it returns, and when to call it. The sibling tools list confirms this is the only account-level operation, so no missing context.

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 schema to explain. The description compensates by explaining what the tool returns, which is more relevant for expected output than parameters. Baseline for 0 params is 4, and the description fully satisfies that.

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 tool's purpose: it returns account email, monitor count/limit, and plan limits. This is a specific verb-resource pair ('get account') that is distinctly separate from all sibling tools, which focus on monitors, incidents, channels, etc.

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?

Explicitly suggests using this as a 'good first call to verify the API key works,' providing clear context for when to use it. It doesn't mention alternatives or exclusions, but the uniqueness of the account-level operation makes alternatives unnecessary.

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