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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), yet the description still adds real value: the taxonomy of checks it performs (off-platform payment, refusing Vinted verification, iCloud/Google lock, named fault, box only) and its provenance ('the same text checks Pouncio's buying bots run before paying'). It stops short of noting limits such as false positives or that matched text is surfaced only within the quoted words, so not 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 usage trigger, then exclusions, then return semantics — a sensible order. The parenthetical examples are illustrative and earn their place, though the single dense paragraph could be broken up for faster scanning.

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?

There is no output schema, and the description compensates by stating exactly what comes back ('each warning sign in the quoted words'), plus language coverage and scope boundaries. Nothing an agent needs in order to call this correctly for a one-parameter read-only tool 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 coverage is 100% and the parameter is already described, so the baseline is 3; the description earns above that by constraining the input to quoted/pasted text and declaring seven supported languages, which the schema does not say. It still adds no guidance on malformed input or the 4000-character cap beyond the schema.

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 ('check ... listing for red flags') and names exactly what input it consumes (a quoted seller/buyer message or listing description). It explicitly separates itself from check_resale_price and check_listing_deal, so an agent can route without opening a 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?

Gives concrete trigger examples ('A Vinted seller wrote: "pay me on WhatsApp..."'), then explicit exclusions: no quoted text, prices go to check_resale_price, bare links go to check_listing_deal. Both when-to-use and when-not-to-use are stated with the named alternative.

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