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

With no annotations provided, the description carries the full burden of behavioral disclosure. It clearly states the operation is read-only, reference data only, and does not submit anything, while also disclosing the sort order. This is strong for a simple list tool, though it does not mention pagination or limit behavior explicitly.

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?

Three tight sentences, each earning its place: the first defines the core operation and sort, the second establishes read-only safety, and the third gives the use case. No filler or redundant restating of the tool name.

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 simple read-only reference tool with only two optional parameters, the description covers what the tool does, its filter behavior, and its intended use. It does not describe the return shape or enumerate valid category values, but given the absence of an output schema and the open-ended string category, the description is largely sufficient for correct invocation.

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 schema describes only the category parameter, leaving limit undocumented (50% coverage). The description compensates for category by explaining its purpose and giving examples, but it says nothing about limit, its default, or its bounds, so an agent gets only partial parameter guidance.

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 uses a specific verb ('List'), names a concrete resource ('curated directories a product can submit to'), and adds a distinguishing feature ('sorted by domain authority'). It clearly differentiates from sibling tools like list_public_listings and list_tracked_sites by focusing on submission-worthy curated directories.

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?

The description explicitly states the intended use case ('Use to suggest where a product should get listed') and includes a clear exclusion ('this does NOT submit anything'). It does not name alternative tools or explicitly say when not to use it, but the context is clear enough for an agent to select it appropriately.

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