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

Annotations already declare readOnly/openWorld/idempotent/non-destructive, so the safety profile is covered. The description adds genuinely useful behavior beyond that: results are paginated, content is localized to the requested language, and prices are returned in the requested currency. It does not describe pagination mechanics or rate limits, keeping it out of 5 territory.

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?

Markdown headers make it scannable, but there is meaningful redundancy: 'What You Get' largely restates the Overview (localized content, prices in currency). The Quick Start contradicts the actual schema, so a full sentence is spent on unusable advice.

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 read-only search with annotations covering safety and no output schema, the description does describe return content (titles, descriptions, images, ratings) reasonably well. The gap is the phantom required query parameters and undisclosed pagination/filter mechanics, which leaves an agent unsure how to actually invoke it.

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?

With zero parameters the baseline would be 4, but the description asserts that 'required `language` and `currency` query parameters' must be provided while the input schema exposes an empty properties object. That guidance is unverifiable and potentially misleading to an agent, pulling the score down to a 3.

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+resource ('Search available tours and activities') with the added scope of localized content and currency pricing. It is clearly distinguishable from sibling reads like getExperienceTour or getExperienceTourAvailability. However, it does not explicitly contrast itself against those siblings, so it stops short of a 5.

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 'When to Use' block gives real context (tours listing, destination pages, category browsing), which is better than nothing. But it never names an alternative tool or a when-not-to-use condition, and it advertises filtering 'by type, duration, or rating' that no sibling/schema actually exposes, so the routing guidance is partly unactionable.

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