Search Listings

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

The description discloses key behaviors beyond the schema: it makes live network calls to Facebook, is rate-limited, takes a few seconds, and does NOT write to the tracking database. These are critical side effects and constraints that an agent must know.

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?

The description is two sentences, direct, and free of fluff. It front-loads the primary action and then provides important behavioral notes. Excellent structure.

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?

The description covers purpose, usage timing, and side effects, which is sufficient for a simple search tool. It does not describe parameters (counted in parameter_semantics) or error behavior, but since an output schema exists (not shown), lack of return details is acceptable. Overall it provides enough context to call the tool correctly.

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?

The input schema has 4 parameters, none of which are described in the schema. The tool description only implies the query is the search term but never explains limit, max_price, or min_price. With 0% schema coverage, the description should compensate, but it does not address any parameter meaning.

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 clearly states the tool's function: 'Search Facebook Marketplace live, right now.' It also differentiates from the daily scan tool by noting it's for one-off questions, making the purpose unambiguous.

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 explicitly advises when to use this tool ('use this for one-off questions') and when not to rely on it for collection ('let the daily scan do the collecting'). It also warns about rate-limiting and latency, setting expectations for usage.

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