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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, and the description adds useful context beyond them: ready=false means the underlying service is unavailable, and the call is a free cached runtime read with no external probe or side effects. This gives the agent a clear behavioral model with no contradiction.

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 compact and front-loaded: the core purpose appears first, followed by the ready=false meaning, behavioral exclusions, and a pointer to the sibling tool. Every sentence earns its place with no 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 only one parameter, an output schema, and strong annotations, the description covers everything an agent needs: purpose, behavior, exclusions, and the alternative tool. Nothing important is missing for selecting and invoking this tool correctly.

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 single parameter is fully covered by the schema, including an enum and a description. The tool description adds contextual meaning by explaining that the selected service's readiness, limits, pricing, and retention are inspected, which enriches the bare schema description without duplicating it.

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 names a specific verb ('Check') and a clear resource ('selected service'), and specifies exactly what is checked: runtime readiness, input limits, pricing, and retention. It also distinguishes itself from get_utility_example by explicitly pointing to that sibling for fixed integration samples.

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 states this should be used 'before use' of a service and lists explicit exclusions: no external probe, payment, analysis, or historical document retrieval. It also names get_utility_example as the alternative when a fixed integration sample is needed, giving an agent a clear routing rule.

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