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

With no annotations available, the description must disclose behavioral traits, but it only states a static fact about comments. It does not mention return format, side effects, authorization needs, or any constraints—completely inadequate for a tool that presumably reads data.

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 extremely short but this is under-specification rather than effective conciseness. It lacks structure and fails to convey essential information, making it unhelpful for an agent.

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 one-parameter tool with no output schema, the description should at least indicate what the tool returns or how to interpret results. It provides none of that, making it impossible for an agent to use the tool correctly without external knowledge.

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 covers the single parameter 'id' with description 'ID of the listing.' at 100% coverage, so the schema already documents it. The description adds no additional meaning, but the baseline of 3 is appropriate since the schema is sufficient.

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 'Comments on a live listing.' does not state an action or verb—it merely echoes the tool name without explaining what the tool does (e.g., lists, retrieves, or creates comments). It fails to distinguish itself from siblings like list_listings or get_listing, providing no clear resource or operation.

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 guidance on when to use this tool versus alternatives. No context about prerequisites, filtering, or scenarios is provided, leaving the agent to guess when to invoke it.

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