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

Annotations already cover destructiveHint=true and readOnlyHint=false, so the mutation is already clear. The description adds valuable behavior beyond annotations: the operation is reversible and requires a two-step confirm ('Two-step: confirm: true to execute'). No contradiction with annotations is present.

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?

Two sentences with no filler. The core action is front-loaded ('Block network access'), followed by the key behaviors (reversibility and confirmation requirement). Every phrase 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?

For a simple two-parameter mutation tool with strong annotations and full schema coverage, the description covers the essential behavior: what it does, that it is reversible, and that confirmation is required to execute. No output schema exists, so return-value explanation is not needed.

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 100%, so parameters are already fully documented in structured form. The description's mention of 'confirm: true to execute' largely echoes the schema's own parameter description and does not add new semantic meaning beyond what the schema 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 states a specific verb and resource: 'Block network access for an eSIMfly-network eSIM'. It also distinguishes itself from the sibling activate_esim by noting the operation is 'reversible with activate_esim', so an agent can tell suspension apart from activation or cancellation.

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 description clearly implies when to use the tool: when network access needs to be blocked for an eSIM. It provides context about the two-step confirm flow and points to activate_esim as the reversal path, though it does not explicitly list exclusions or contrast with cancel_esim.

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