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

Annotations already declare the mutation profile (readOnly=false, idempotent=false, destructive=false). The description adds real context beyond that: receipts are additive and never retroactive, negatives are logged as corrections, and item.on_hand is the mutated field. It does not cover whether the item must already exist, what happens on an unknown item_id, or permission requirements, so it sits at adequate rather than rich.

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?

Four short sentences, front-loaded with the core effect, then the non-retroactivity rule, then the correction workflow, then the mutated field. No filler and no repetition of the schema.

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 3-parameter mutation with no output schema, the description covers the effect on state and the correction path, which is the critical information. Gaps remain around preconditions (existing item id) and what the response returns, but annotations and the schema carry most of the rest.

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%, so baseline is 3, but the description adds meaning beyond the schema: it explains why a negative qty exists (count correction) and that such a receipt is visible as a correction in the log. It says nothing about note or item_id beyond what the schema already documents.

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?

Opens with a specific verb and resource: "Increase quantity on hand for a stocked item." It implicitly distinguishes itself from count-correction flows by stating receipts are additive and never retroactive, but it never names a sibling (e.g. inv_count_stock or p2p_receive_goods), so the agent must infer the boundary.

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 clear when-to-use guidance, including the non-obvious case: to correct a count, receive the difference with a negative qty. It lacks an explicit "use X instead" routing statement against the many inventory/purchasing siblings, which keeps it below a 5.

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