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

Beyond the annotations, it discloses two non-obvious behaviors: a locked rule stays locked until the owner revises it, and existing entries require expectedRevision (an optimistic-concurrency requirement). 'Identical retries leave history unchanged' restates idempotentHint=true rather than adding new information, but the locking and revision preconditions are genuinely additive given destructiveHint=true.

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?

Five short sentences, each carrying a distinct rule, with the core action front-loaded ahead of the caveats. No filler, though the idempotency sentence slightly duplicates the annotation.

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?

An output schema exists, so return values need no explanation, and the description covers mode selection, locking, concurrency, and retry behavior. The main gap is the status enum's meaning, which matters for a tool whose required field is status.

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 8 parameters, so the description must carry the load. It clarifies decision (APPROVED/NONE) and adds the conditional requirement on expectedRevision, but says nothing about status (LOCKED/DEVELOPING/UNKNOWN/RETIRED), productId, title, tags, or revisionReason, leaving most of the surface 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 verb and resource ('Save ... discount or the rule that no discount is approved') and unpacks the two decision variants (APPROVED vs NONE), so an agent knows exactly what is being written. It does not name any sibling tool (e.g., revise_approved_fact) to differentiate, which keeps it short of a 5.

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?

It gives clear selection criteria for the two modes: decision APPROVED stores only owner-supplied terms, decision NONE records the absence of approval, plus the guardrail 'Do not invent a discount' and the precondition that existing entries require expectedRevision. No explicit when-not or named alternative is offered, so it is not a 5.

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