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

With no annotations provided, the description carries the full burden of disclosing behavior. It explicitly says the tool provides evidence rather than a safety rating and that Clearhouse never selects or executes on the user's behalf, which is a meaningful behavioral boundary. It also hints at the live-probe nature of the data, though it could be clearer about whether invoking the tool triggers new probes or returns precomputed facts.

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 front-loaded with the core content: observed facts, probe results, call history, and summary index. The closing disclaimer about evidence vs. safety rating is valuable context and not excessive. It is slightly longer than necessary but every sentence adds meaning.

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 tool with one simple parameter and an output schema, the description covers the key context: what data is returned, the confidence tier, and the intended decision-support role. It does not explicitly state side effects or error cases, but the 'never selects or executes' line covers the most important behavioral edge. Overall, it is complete enough for an agent to call it appropriately.

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 only one parameter, listing_id, but schema description coverage is 0%, so the description must compensate. The description says 'about a listing' but never explains the listing_id parameter, its format, or how to obtain it. This leaves the agent to infer the parameter meaning entirely from the property name.

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 what the tool does: it returns observed facts about a listing, including live probe results and routed-call history. It specifies the resource ('listing') and the type of data returned, making the purpose concrete. However, it does not explicitly distinguish itself from sibling tools like index_stats, which could also return index-like statistics.

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 provides clear usage context: this is evidence for the caller's own decision, not a safety rating, and Clearhouse never selects or executes on the caller's behalf. This tells the agent when to use the tool and what not to use it for. It does not name alternatives or explicit conditions for sibling tools, so it stops short of a 5.

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