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

Annotations only cover the safety profile (readOnly, non-destructive, closed-world); the description adds substantial behavioral context: data provenance (append-only Catalog Items history, weekly Listings Items snapshots), the row-per-changed-field shape, and a critical edge case where first-snapshot accounts return 'insufficient retained history' instead of a misleading 'no change'.

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?

Three dense sentences with the core purpose front-loaded and no filler, though the middle sentence is heavily jargoned and packs both source systems and the full field list into one breath. Every sentence earns its place, but readability suffers slightly from density.

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 10-parameter read tool with an output schema and full schema description coverage, the description supplies everything an agent needs: scope, sources, coverage limits, and the insufficient-history fallback behavior. Return values are correctly left to the output 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 every parameter is already documented in the schema (including the sku/asin distinction and the date-vs-lookback logic). The description only restates the field list and the generic_keyword source, adding no syntax or interaction detail beyond the schema, so the baseline 3 applies.

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 ('Return factual listing-content changes') and then enumerates exactly which fields are diffed and from which two sources. An agent can distinguish it from get_listing_registry, get_listing_quality, or get_action_history purely from this text.

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?

Implies the usage context clearly and justifies itself against the absent native option ('Amazon exposes no native listing edit-history API'), and it defines a boundary ('Video and A+ module content are not diffed'). It does not, however, name a sibling alternative to prefer for adjacent questions, so it stops short of explicit routing guidance.

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