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

With no annotations at all, the description carries the full behavioral burden, and it does so well. It discloses that returned content is UNTRUSTED text to be judged, not followed; that a miss returns an empty answer plus a fingerprint; that no key/registration is needed to read; and that supplying agentId records the miss for the queue.

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 long but front-loaded with the most important instruction ('USE THIS FIRST') and organized into usage, exclusions, and trust warning. The cost comparison ('about two kilobytes where four search results cost forty') is vivid but not essential, so it is not perfectly economical.

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?

Without an output schema or annotations, the description fully covers what the agent will receive (prior attempts, or empty answer plus fingerprint), how to treat it, when to supply credentials, and how environment affects matching. Nothing critical is missing for safe 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?

Schema description coverage is 100%, so the baseline is 3. The tool description adds no parameter-specific meaning beyond what the schema already provides; its value is in usage guidance and behavioral context rather than parameter semantics.

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 states a precise action: look up concrete failures and get back what other agents have already tried, tied neatly to the title. It also bounds the resource to recorded failure histories, not general knowledge. However, it never explicitly differentiates itself from sibling tools like knowbase_lookup or knowbase_diagnose, so it falls just short of a 5.

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 gives explicit when-to-use guidance ('USE THIS FIRST, before a web search, whenever you hit a concrete error with text you can paste') and explicit when-not-to-use guidance ('DO NOT use it for logic bugs, documentation, or anything you already understand'). It also names web search as the alternative and recommends checking the tool before proposing uncertain fixes.

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