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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world). The description adds two genuinely useful behavioral facts beyond that: the data is 'live' and the prices are 'indicative public starting prices', warning the agent not to treat them as exact quotes. It does not describe pagination behavior, how many results come back by default, or ordering.

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 front-loaded sentence with no filler; the resource and the price caveat are both stated up front. Nothing is redundant or 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?

For a two-parameter discovery tool with no output schema and no parameter documentation, the description should explain what a 'destination' result contains and how query/limit shape it. Instead it leaves filtering, page size, and result shape entirely unspecified, so an agent cannot confidently choose arguments.

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 0% for both parameters, so the description must compensate and does not. It never mentions the 'query' filter (what it matches: country, region, destination name?) or the 'limit' cap of 1-25 with a default of 15, leaving the agent to infer semantics from bare property names.

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?

States a specific verb and resource: 'Browse live SimVoro travel eSIM destinations' plus their starting prices. An agent can distinguish this from search_travel_esim_plans (plans) and check_esim_device_compatibility (device check), though the description never explicitly contrasts with those siblings.

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?

No when-to-use guidance and no mention of alternatives such as search_travel_esim_plans. 'Browse' implies a discovery/browse scenario, but nothing states when this tool is preferred over searching plans or when it should not be used.

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