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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered. The description adds only 'public' and 'caller-supplied', saying nothing about what happens if the URL is not a valid Leboncoin listing or whether the page must be a listing vs. any page.

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?

A single short, front-loaded sentence with no waste. It is terse to the point of under-specifying, but there is no padding or redundancy to trim.

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?

An output schema exists, so return values need not be described, and the tool is a simple one-parameter lookup. However, for a tool whose only input is a URL, the omission of any URL-format or validity constraint leaves a real 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 description coverage is 0% for the single required 'url' parameter, so the description must carry the burden. It only implies a caller-supplied value without stating that the parameter is a full Leboncoin listing URL, its expected format, or whether search/other URLs are accepted.

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 ('Get') and resource ('public Leboncoin listing'), and 'caller-supplied' signals that the identifier comes from the caller. It does not distinguish itself from the sibling leboncoin_search, so an agent must infer the difference (single listing by URL vs. search).

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?

There is no when-to-use guidance, no mention of prerequisites, and no reference to leboncoin_search as the alternative for discovering listings. The agent is left to infer that this tool only works when it already has a URL.

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