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

Annotations already declare destructiveHint=true, idempotentHint=false, and openWorldHint=true, so the safety profile is covered. The description adds genuinely non-obvious domain semantics beyond that: pinning is not a retention extension and not a recovery authorization. It still omits conflict/expected_revision behavior, but the added context is real.

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 action and followed by the key constraint; no filler, no redundancy. Every sentence 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?

With 5 required params, 0% schema coverage, no output schema, and a destructive non-idempotent mutation, the description is too thin. An agent gets no guidance on the required revision/concurrency parameter, error conditions, or what the call returns.

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 5 required parameters, so the description must compensate — and it largely does not. 'Pin or unpin' only weakly implies the `pinned` boolean; app_id, environment, checkpoint_id, and especially expected_revision (optimistic concurrency) go entirely unexplained.

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 pair and resource: 'Pin or unpin a version in app history.' This clearly distinguishes it from creation/restore siblings like beon_create_app_checkpoint or beon_prepare_app_checkpoint_restore, though it never names those siblings explicitly.

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 second sentence provides negative scoping (does not extend backup retention, does not grant recovery permission), which steers the agent away from treating this as a protection/recovery tool. However, there is no positive when-to-use guidance or explicit alternative named, leaving usage largely implied.

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