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

With no annotations, the description carries the full burden; it does disclose the return content (failure categories with counts, task-attributable failures, designed fixes and their status) and the source population (the unchanged agent or the best agent it built). It omits whether the call is strictly read-only, how fresh the data is, what happens when there are no recorded misses, and cost/latency, leaving real behavioral gaps for a no-annotation tool.

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 key idea, "Why agents fail", is front-loaded, but the body is a single run-on sentence with abstract phrasing like "as OPSIN read it" and "the lines it designed from them with where each stands" that requires re-parsing. It would be clearer as a short list of what the response contains, and some of the hedging ("A reading, not a signed result" is fine; the double parenthetical is not) could be trimmed.

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?

With only two optional parameters and no output schema, the description is the only place return values can be explained, and it does describe the four sections of the response and the population being analyzed. What remains missing is failure/empty-state behavior and confirmation of read-only semantics, which matters given the absence of annotations.

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 coverage is 100% and both params are documented enums, so the baseline would be 3. The description adds genuine meaning by framing both as narrowing filters and by pointing the agent at opsin_suites to discover valid suite values, which the schema itself references but does not resolve.

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?

"Why agents fail" plus the elaboration about readings of an agent's misses on tasks with known answers establishes a specific resource: failure-mode diagnostics over benchmarked runs. It never names or distinguishes itself from nearby siblings such as opsin_verdict or opsin_status, so an agent must infer that this is the analysis view while those are the verdict/status views.

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?

"Narrow it with suite and thinking" tells the agent how to scope the call, and "A reading, not a signed result" implies it should not be treated as a verdict. There is still no explicit when-to-use statement, no statement of when to prefer opsin_verdict, and no prerequisites, so usage is only implied.

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