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

Annotations only declare readOnlyHint=true, but the description adds substantial context beyond that: currentCogs null meaning, missingOnly filtering, that total is returned with pagination, and that Vendor Central (1P) rows carry a `channel` field distinguishing SELLER vs VENDOR. This is exactly the extra behavioral detail the annotation can't convey.

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 return shape and scope, then the usage workflow, then pagination and the channel caveat. Dense but well-ordered; the parenthetical detail is efficient. A touch long but every clause carries information.

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 must describe return values — and it does thoroughly (row granularity, currentCogs null, total, channel per row, missingOnly filtering). Given 6 params at 67% coverage, an agent has what it needs to call and interpret the result correctly.

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 67%, and the description adds value on top: it explains limit/offset pagination returns total, clarifies missingOnly semantics, and mentions the `channel` field appearing on each row. It doesn't elaborate on region or accounts, but those are well documented in the schema, so the incremental gain is solid but not exhaustive.

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?

Names the specific resource (one region's COGS worksheet) and precisely describes its contents: a row per (account, ASIN, SKU) catalog product and per cost period/batch, with currentCogs. This distinguishes it cleanly from the other worksheet siblings (get_fbm_worksheet, get_vat_worksheet, etc.) as the COGS 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?

Explicitly routes the agent: 'Use it to match a seller's source file to exact SKUs/ASINs before building import_cogs rows' names the downstream sibling and the prerequisite step, and 'read a SKU's full FIFO ladder before restating it' gives a second concrete use case. Match-by-SKU-then-ASIN precedence is spelled out.

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