Fugu second opinion (review)

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

No annotations are provided, so the description carries the full burden. It discloses that Fugu is a separate LLM, acts as a skeptical senior reviewer, and returns 'concrete issues, risks, and improvements.' It also notes that Fugu cannot see the repo or conversation, and that all context must be in 'content.' While it could mention potential timeouts or output format, the description provides sufficient behavioral context.

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 concise (3-4 sentences) and front-loaded with the core purpose. Every sentence adds value: purpose, best use case, constraint, warning, and performance note. No unnecessary words.

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?

Given the absence of an output schema, the description explains return values as 'concrete issues, risks, and improvements.' This is sufficient but could be more specific (e.g., format). The tool has three well-documented parameters and clear usage guidance, leaving minimal gaps. A minor omission is lack of mention of rate limits or output length.

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%, with each parameter having a detailed description in the schema (e.g., 'content' includes examples of what to review). The tool description does not add additional parameter-level semantics beyond the schema, so the baseline score of 3 is appropriate.

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 purpose: 'Get a rigorous SECOND OPINION from Sakana Fugu on a discrete piece of work.' It specifies the verb (get), resource (second opinion), and scope (discrete piece), and differentiates from the sibling 'ask_fugu' by emphasizing cross-checking and skepticism.

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 explicit guidance: 'Best for cross-checking your own output with a different model on a self-contained artifact.' It also states when not to use it: 'Do NOT use it for interactive/iterative repo work or anything needing local file access.' Additionally, it mentions performance ('Calls can be slow'), giving clear context for use.

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