Items Validate

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

The description discloses the exact return shape {ok, problems, schema, count} and the success condition (ok is True iff problems is empty), which goes beyond the readOnlyHint annotation. It also details the validation checks performed, giving the agent a concrete model of behavior. It does not mention missing-file error handling, but the read-only safety profile is already covered by annotations.

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 action, then follows with specific checks, domain context, and the return value. It includes some extra background (the '#140 C1' reference and part-number semantics) that could be trimmed, but each part contributes to understanding the tool's scope. Overall it remains well organized and not bloated.

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 string parameter and no output schema, the description covers the essential ground: what is validated, the input meaning, and the return format. It does not enumerate every possible problem type or describe behavior when the registry file is missing, but an agent has enough information to select and invoke this tool correctly.

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 provides only the parameter name 'registry' as a string with zero description coverage. The description fills this gap completely by stating it is 'path to the items.json sidecar', which is essential information for the agent to invoke the tool correctly. This goes well beyond the schema.

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 opens with a clear verb+resource: 'Validate an items.json registry', then enumerates the exact checks (schema stamp, record shape, unique part numbers, reserved rev/lifecycle fields). This is specific enough to clearly distinguish it from sibling item tools like items_resolve or items_new, even without naming them.

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 clear context: this tool is for validating the items.json sidecar, with an explicit single parameter (path to the registry). It does not name alternatives or exclusions, such as when to prefer items_check_manifest, but it is unambiguous about its purpose and input.

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