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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and closed-world, so the safety profile is covered. The description adds a useful privacy constraint ('Never provide personal data') and names the scenario outcomes, which is legitimate added context, though the return values are largely restated by the existing output schema.

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 short sentences, front-loaded with the core behavior and immediately followed by the hard constraint. Every clause carries information and nothing is 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?

With an output schema present, return values need not be explained, and annotations cover safety, so the main remaining gaps are the meaning of 'country'/'capability' and the relationship to sibling tools. For a 3-parameter tool at 0% schema coverage this is adequate but leaves real ambiguity.

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%, so the description must carry parameter meaning. It does effectively enumerate the accepted 'scenario' values (match/mismatch/not_found/timeout/unsupported), which compensates for that one parameter, but it says nothing about what 'country' or 'capability' mean, leaving two of three parameters undocumented.

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 action (return) and object (synthetic fixture) and enumerates the scenario types produced, so the agent knows this generates test fixtures. It does not explicitly distinguish itself from the sibling get_sandbox_verification, which is its read counterpart, so sibling differentiation is only implied by the word 'create'.

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 scenario names (match/mismatch/not_found/timeout/unsupported) imply this is for sandbox/testing purposes, but there is no explicit statement of when to use this versus get_sandbox_verification, plan_verification, or explain_result. Usage context is inferable but not stated.

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