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

Annotations already cover read-only/idempotent/open-world safety, but the description adds genuinely new behavioral context: the affiliate-link commission disclosure, that Viator confirms final price/availability/cancellation terms before payment, and that dates filter to Viator-listed availability. Minor redundancy in restating 'Read-only.'

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?

Front-loaded with the core purpose, and each sentence carries information (dates, sorting, affiliate disclosure, price confirmation). The middle return-field enumeration is a dense run-on and partially duplicates the output schema, but nothing is truly wasted.

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 an output schema present, the field list is redundant yet harmless, and the description still covers the commercially important details (affiliate link, third-party price confirmation, date-based availability). It omits pagination/limit behavior, which is the main remaining gap for a 10-parameter search tool.

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 coverage is only 40% across 10 parameters, so the description must carry weight; it does add meaning for sort/date interactions and the 'featured' ordering, plus concrete q examples. However it says nothing about the other undocumented parameters (limit, page, currency, max_price, min_rating, free_cancellation), so it only partially compensates.

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 a specific verb and resource ('Live search of bookable tours and activities in Bangkok, Thailand from Viator's partner API'), and the data source plus geographic scope implicitly separate it from generic siblings like search_listings. It never names the sibling it differs from, so the differentiation is inferable rather than explicit.

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 the Bangkok-tours scope, and it explains when start_date/end_date narrow results and how the default order behaves. There is no explicit 'use this instead of X' routing against search_listings or any when-not condition, leaving the agent to infer the boundary.

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