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

Adds substantial context beyond the annotations: the draft-only lifecycle gate, the credit-gate rationale for why confirmed lines are immutable, and the replace-all effect on existing lines. It does not cover permissions or whether the credit gate re-evaluates amended lines, which keeps it off a 5.

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?

Front-loaded with the core action and constraint, and the lifecycle/alternative guidance earns its space. The closing "Effects: order lines replaced." restates the first sentence, and the mid-sentence line break hurts readability slightly.

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?

For a 2-parameter, fully-described schema with annotations present and no output schema, the definition covers everything an agent needs to decide and call correctly. Only the post-amend re-evaluation behavior is left implicit.

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 coverage is 100% and the schema already says "The new full set of lines," so parameter semantics are largely carried by structured fields. The description reinforces the replace-not-merge semantics, which is useful but only marginally additive over the schema.

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 plus a hard precondition: "Replace the lines of a DRAFT order." It is immediately distinguishable from o2c_create_order (growth) and o2c_close_short (post-confirmation shrink), both of which are named in the body.

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?

Gives explicit when-to-use (draft only) and when-not (after confirmation) rules, and routes the agent to the correct alternative for each non-draft case: o2c_close_short for shrink, a new order for growth. Nothing is left to inference.

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