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

Annotations already declare readOnlyHint/openWorldHint/destructive=false, so the safety profile is covered. The description adds genuine value beyond them by disclosing the data source and freshness (live SP-API vs daily stored snapshots), which the annotations cannot express. Minor gap: no mention of rate limits or freshness lag.

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?

Two sentences, front-loaded with the core action and followed immediately by the mode switch. No filler or restated title text; every clause earns its place.

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 an output schema present, return values needn't be explained, and the description adequately covers the live-vs-history decision for this 7-param tool. It could say more about scoping limit/offset to history mode, but nothing an agent needs to call it correctly is missing.

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 100%, so every one of the 7 parameters is already documented in the schema. The description only adds that date parameters toggle history mode; it doesn't clarify that limit/offset apply in history mode or explain include_diagnostics/include_raw_rows beyond the schema. Baseline 3 is correct when the schema does the heavy lifting.

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 ('Get competitive price points for ASINs') and explains the dual live/history behavior, so the agent knows exactly what it retrieves. It does not, however, differentiate itself from any of the many adjacent pricing siblings (get_listing_offers, get_current_rank, get_offer_listings), so it stops 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?

Gives clear mode-selection context: omit dates for live SP-API data, provide a date window for stored snapshot history. That routes the agent correctly between the two behaviors. It stops at 4 because it offers no guidance against overlapping siblings and no explicit exclusions.

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