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

Annotations already establish this as a safe, read-only, idempotent lookup. The description adds real behavioral context beyond that: the ranking is based on the gap between asking prices and sold prices after buyer protection and shipping, weighted by sales volume, and limited to common electronics categories. It stops short of describing result count, freshness, or output shape, but is substantially informative.

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?

It is front-loaded with the triggering situations, then explains the ranking logic and scope, then closes with exclusions. Every sentence earns its place and there is no wasted preamble.

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 three-parameter, read-only discovery tool with no output schema, the description covers purpose, usage boundaries, ranking methodology, and category scope well. It could more explicitly describe the shape of ranked results, but nothing critical 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 all three parameters are already documented in detail. The description's examples loosely illustrate budget and category usage but add little semantic 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?

The description states a specific verb and resource — ranking models worth flipping — and directly names the sibling tools it is not (check_resale_price, check_listing_deal). An agent can distinguish this tool's role without opening any schema.

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?

It gives explicit trigger examples ('what can I flip with 200 euros?', 'which iPhones are worth reselling?') and explicit exclusions with alternative tools for single-item pricing and listing-link checks. The routing decision is fully specified.

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