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

Annotations already declare readOnlyHint=true, so 'Read-only, books nothing' is largely confirmatory. The real added value is disclosing the failure semantics returned ('minimum stay, too many guests, arrival day, lead time...') and the endpoint mapping, which the annotations and absent output schema would otherwise leave opaque. It omits cost composition (fees/taxes/currency) and any rate-limit or auth notes.

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?

One dense sentence front-loads the core outcome and its failure modes, followed by a two-word safety note and a compact endpoint citation. Every clause earns its place; nothing is padded.

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 no output schema, the description does the necessary work of explaining what comes back (bookable properties plus reasons for the rest). It is slightly under-specified on what 'total price' includes (fees, taxes, currency) and does not mention pagination or result caps for large property sets.

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?

Schema description coverage is 100%, so all six parameters are already documented in the schema, including the customer_id lookup fallback and the 'omit apartment_ids to check all' behavior. The description adds nothing parameter-specific beyond the arrival/departure pairing, so the baseline 3 applies.

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?

Starts with a concrete verb+resource ('Check which properties can be booked for an arrival/departure pair') and adds the value returned ('get the total price for each'). This is clearly separable from list_apartments (inventory) and get_rates (rate lookup) without opening either schema.

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?

Usage is implied by 'Read-only, books nothing,' which signals this is the pre-booking check rather than the booking action (smoobu_create_reservation). However, it never explicitly names an alternative tool or states when not to use it, leaving the routing inference to the agent.

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