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

Annotations already declare read-only, idempotent, non-destructive, closed-world behavior, and the description adds genuinely new context: this is an async request that returns a request_id, the no_install_yet outcome means the profile may have been QR-installed with no Widely app present, and no APN is included.

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?

Three short, front-loaded sentences; the action and return value come first and the edge-case meaning follows. The trailing 'An APN is not included' is slightly cryptic but still earns its place.

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?

No output schema, and the description does cover the request_id return and the no_install_yet semantics, which is helpful. However, it omits how to retrieve the result (the obvious get_esim_connection_check poll) and leaves both input parameters unexplained, so an agent lacks enough to invoke it confidently.

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 sim_id and device_id, so the description carries the full burden of explaining them, and it says nothing about either parameter. The reader cannot tell what sim_id identifies or how device_id relates to the target handset.

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 (check the eSIM connection via the user's Widely app) and notes it returns a request_id, which signals an async trigger. It doesn't explicitly differentiate itself from the sibling get_esim_connection_check, leaving the poll/trigger relationship to inference.

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?

Implies a precondition (the user's Widely app must be reachable) and gives diagnostic context for a no_install_yet result, but never states when to call this versus get_esim_connection_check or the install-step siblings. Usage is implied rather than specified.

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