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

Annotations already declare readOnlyHint=true, openWorldHint=true, and destructiveHint=false. The description reinforces this by framing the tool as informational, and adds the 'Call first' workflow hint. It does not contradict annotations, but it also doesn't disclose additional behavioral traits beyond what the annotations and obvious purpose provide.

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 a single, tightly packed sentence that front-loads the content categories (what, tools, prices, phone) and ends with a crisp directive. 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 0-parameter, annotation-covered informational tool, the description covers the essentials: what it communicates and when to invoke it. It doesn't specify the return format, but that is not necessary for an overview tool of this simplicity, so the completeness is strong.

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 description coverage is 100% (vacuously). The description correctly avoids parameter detail since there are none, matching the baseline for 0-parameter tools.

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 states exactly what the tool provides: an overview of Callstay, existing tools, pricing semantics, and the human desk phone number. This clearly differentiates it from siblings like get_property or search_stays, which are specific operations.

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 instruction 'Call first' explicitly signals that this tool should be used before others, giving clear usage context. It doesn't enumerate exclusions or direct comparisons with alternatives, but the sibling list and the tool's purpose make the intended first-step role evident.

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