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

Annotations already declare readOnlyHint=true, and the description adds behavioral context by listing the specific operational metrics reported, including the 'remaining shared daily registration allowance for AI clients.' This goes beyond the annotation by explaining what the read-only status call exposes without suggesting any side effects.

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?

The description is two sentences with no filler. The main purpose is front-loaded, followed by a compact enumeration of returned metrics and a practical usage note. Every sentence earns its place.

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 status tool with no output schema, the description is complete: it states what the tool reports, the scope of coverage, and when to invoke it. Nothing essential is missing for an agent to decide to call it.

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 parameter semantics do not carry risk. The description still adds value by detailing what the status call returns, satisfying the baseline for a no-parameter tool.

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 uses a specific verb ('Report whether the tracker is running and what it covers') and then enumerates the concrete data returned: hotels, cities, tracked stays, price checks, and registration allowance. This clearly distinguishes it from the sibling tools, which are about prices, deals, hotels, or tracking actions rather than service status.

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 states when it is useful: 'before starting a longer flow, or to confirm the server is live.' This gives clear usage context, though it does not explicitly name sibling alternatives or state when not to use it.

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