amazon_fetch

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

With no annotations, the description carries the full burden and does much of it: it names the four-stage fallback ladder, states fresh sessions are used, that it halts on rate limits, and that raw HTML is large. It doesn't say what happens when all engines fail or whether any local environment (browsers for playwright) is required, which keeps it below a 5.

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 core action and mechanism in the first clause, then parameters, then the return shape. Compact and mostly waste-free, though the line-broken layout scatters related details and the return-value sentence is partly redundant with the output 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 scrape-and-fallback tool this covers the mechanics an agent needs: the engine ladder, the rate-limit stop, and the size warning on raw HTML. An output schema exists so return values needn't be detailed, though the description mentions them anyway; missing failure-mode behavior is the remaining gap.

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 0%, so the description must compensate, and it explains all three: url accepts a public Amazon URL or 10-char ASIN, include_html controls raw-page inclusion and warns of size, and max_engine caps the ladder with the four engine names. Minor gap: max_engine's effect (cap = start-at vs stop-at) is ambiguous.

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 (fetch a public Amazon URL or 10-char ASIN) plus the mechanism (local fetch ladder). It doesn't mention the amazon_product sibling, so an agent must infer that this is the raw-page path and that one is the structured-data path. Still, the scope ('public Amazon URL', 'through a local fetch ladder') is concrete enough to pick it out of a three-tool set.

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 one explicit conditional — 'Set include_html=true only when you need the raw page (large)' — and a stopping condition ('Stops on rate limits'), which is real guidance. However, it never says when to prefer this over amazon_product, and the exclusions are limited to a single parameter.

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