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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds content detail (the named promotion types and their conditions) but says nothing about freshness, completeness of the offer list, or whether conditions are returned verbatim — modest added value beyond the annotations.

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?

A single tight sentence with no filler, and the examples are front-loaded to make the scope concrete. It loses a mark only because the noun-phrase framing is slightly less immediately actionable than a verb-led statement.

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 simple zero-parameter read with no output schema, the description conveys enough about what comes back (promotions and their conditions) to set expectations. It could be more complete by indicating whether the offers are site-wide or tied to specific villas/dates, but nothing essential for calling it is missing.

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 takes zero parameters, which is the baseline-4 case: there is no parameter semantics for the description to explain, and it correctly implies a no-argument retrieval.

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 resource — the promotions on book.dhananjaya.id — and concrete examples (Best Rate Guarantee, Early Bird, Stay Longer) plus their conditions, which clearly separates it from siblings like check_availability and villa_details. It is expressed as a noun phrase rather than an explicit verb, so it states what the tool exposes rather than what action it performs.

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?

Usable context is implied: an agent asking about current deals or promotional terms would naturally call this. However, there is no explicit when-to-use statement, no mention of how it complements check_availability or villa_details (e.g. whether offers can be combined with a quote), and no exclusions.

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