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

Annotations already establish that this is a safe, read-only, idempotent, non-destructive operation. The description adds useful context by specifying the pricing basis (1 GB · 7 days) and that the tool returns network-level details, but it does not discuss rate limits, freshness, or result shape.

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?

The description is a single dense sentence with no filler. It front-loads the resource and scopes the returned data efficiently, though the parenthetical pricing detail makes it slightly hard to parse at first read.

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 tool with no output schema, the description sufficiently covers the returned fields and the pricing reference. It does not describe the return container or pagination, but annotations and the schema handle most remaining safety and parameter concerns.

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 75%, leaving mainly currency undocumented. The description reinforces that only one country is queried but adds no syntax or format guidance for bucket, currency, language, or destination beyond what the schema already provides.

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 clearly identifies the resource (mobile networks available per country) and the exact data returned: operator name, 4G/5G, and a reference eSIM price per network. It does not explicitly name or contrast with sibling tools, so it falls 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?

It implies the tool is used to determine which network is cheapest and what others add, but it does not state when to use it instead of alternatives such as price_grid or recommend_config. Usage is inferable but not explicit.

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