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

Beyond the readOnly/non-destructive annotations it discloses the READ:PRODUCT permission requirement, the endpoint used (/v3/stock vs /v3/stock/{inventoryUuid}), that untracked products are silently omitted, and that results are paged via next_cursor. These are real operational facts an agent needs and cannot get from annotations.

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 clauses, each carrying distinct information (payload fields, scoping switch, inclusion filter, permission, paging, endpoints), with the core purpose front-loaded. No filler or redundancy.

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 no output schema, the description does the job of naming the returned fields and explains paging, permissions and filtering. It stops short of clarifying what 'balance' includes (available vs reserved) or the page-size default, though the latter is in the schema.

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 the baseline is 3; the description adds meaning by spelling out the behavioral difference between supplying and omitting inventory_uuid and by tying paging to next_cursor. It adds nothing on limit bounds, but the schema already covers that.

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+resource: it returns stock balances per product variant and enumerates the fields (balance, low-stock level/alert, last update). It does not distinguish itself from the close sibling zettle_get_stock_for_products, which an agent could easily confuse with this one.

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 scoping rules: with inventory_uuid it returns that single store's inventory, without it returns all stores, and only inventory-tracked products appear. It lacks explicit when-to-use/when-not guidance relative to zettle_get_stock_for_products or list_products, so no exclusions are stated.

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