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

The annotations already declare destructiveHint=true, idempotentHint=false, and openWorldHint=true, so the safety bar is partly met. The description adds genuinely useful context beyond them: newer data may be discarded and charges may apply, which the annotations do not convey.

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 that leads with the action and then appends the two risk caveats. Dense but well-ordered; every clause carries information, though the semicolon-joined clauses could be split for scanability.

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?

There is no output schema, so the description need not explain return values, and the annotations cover the safety profile. However, for a destructive 10-parameter tool with 0% schema coverage, the absence of any parameter explanation or alternative-selection guidance leaves a real completeness gap.

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% across 10 parameters, so the description must carry the load and largely does not. It gestures at targetTimestamp ('to a timestamp') and newServiceName ('create recovery services') but says nothing about volumeInstanceId, the beon_* fields, or approval_id, leaving most 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?

States a specific verb and resource ('Restore persistent storage to a timestamp'), which distinguishes it from the sibling railway_restore_volume_backup by implying point-in-time recovery rather than backup restoration. The purpose is clear without opening the schema, though it does not explicitly name the sibling it differs from.

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 guidance on when to use PITR over railway_restore_volume_backup or the other volume tools, and no mention of prerequisites such as approvals. The two outcome modes ('discard newer data' vs 'create recovery services') are named but never tied to a condition for choosing between them.

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