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

Annotations already declare the write/idempotent/non-destructive profile, so the burden is lighter. The description adds one behavioral fact beyond the schema: this only works under the caller's active lease. It does not explain what happens on a stale lease, whether prior checkpoints are superseded, or the return shape.

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?

One front-loaded sentence that packs the stored contents and the lease precondition with no wasted words. It is efficient, though it stops short of routing guidance that would make the sentence fully earn 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 exists, so the description could say more about the result. For an 8-parameter mutation with 25% schema coverage and no return documentation, the definition is adequate but leaves meaningful gaps around the lease/fencing model and the sibling boundary with leave_checkpoint.

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 only 25%, so the description should compensate. It semantics-maps several free-form params (current state, open questions, next steps, linked attempts), which helps, but task_id, summary, and the lease/idempotency semantics are left to the schema or 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?

Specific verb ("Save") plus resource (resumable task state / checkpoint), and it enumerates the payload fields that will be persisted. It does not, however, distinguish itself from the close sibling leave_checkpoint, so an agent must infer which one to use.

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?

"Under your active lease" implies a precondition (an active lease must exist), which is useful context. But there is no explicit when-to-use versus leave_checkpoint/record_attempt, no when-not-to-use, and no routing to an alternative. Usage is implied rather than stated.

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