diagnostic_explain

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

Annotations already cover safety (readOnly, idempotent, non-destructive, closed-world), and the description adds substantial context beyond them: the tool runs inside an app that must be installed and licensed, an unknown code returns an error listing known codes, and the explanation explicitly avoids promising that an action will improve the verdict. This is rich, non-obvious behavioral disclosure.

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?

Content is dense and every sentence carries information, but the opening paragraph is a long environment/licensing preamble before the actual function is stated. It is efficient overall, though the ordering pushes the app-install requirement ahead of the core purpose.

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 no output schema, the description compensates by describing what the returned explanation contains and how errors surface. For a single-parameter read-only tool, nothing an agent needs to invoke it correctly is missing.

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%, so the single 'code' parameter is fully documented, including example values ('OF01', 'OF03', 'CO01'). The description reinforces the provenance (codes from red_flag_check violations) but adds no syntax or format detail beyond the schema, so the baseline 3 applies.

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?

States a specific verb and resource — 'Explain one diagnostic code' — and enumerates exactly what the explanation contains (what the quantity measures, why it matters, which measurement could move the verdict). It also cleanly distinguishes itself from siblings diagnostics_catalog (lists all codes) and red_flag_check (source of codes).

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?

Explicitly says to use it on codes returned by red_flag_check and to list every code with diagnostics_catalog, i.e. it names both the trigger source and the alternative tool. It also states the prerequisite (Stochastly desktop app open with an Atelier or Portfolio licence) and the failure behavior for unknown codes.

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