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

Annotations already declare read-only and non-destructive behavior, so the description does not need to restate that. It adds meaningful behavioral context beyond annotations: restricted items have their text fields stripped and restricted_count reports how many. This is important non-obvious behavior for interpreting results.

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?

Two sentences with no filler. The core action is front-loaded, and the restricted-item caveat is delivered efficiently. Every word earns its place.

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 simple read-only text search with an output schema present, the description covers the essential behavior, including the main quirk about restricted items. It doesn't provide usage guidance or search syntax details, but annotations and output schema carry some of that burden, so the description is reasonably complete.

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 0%, so the description must compensate. It clarifies that 'q' is a text query and mentions restricted_count as an output signal, but it does not explain search matching semantics or add detail about the limit parameter beyond what the schema already provides. Partial compensation but not complete.

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?

Description states a specific action ('Search items by text') with a clear resource ('items') and mechanism. It also distinguishes itself from lookup-style siblings and adds a unique scoping detail about restricted items. The verb+resource pairing leaves little ambiguity about what this tool does.

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 implies this tool is for text-based search over items, which is reasonably clear given sibling names like lookup and list. However, it never explicitly states when to choose this over principia.items.lookup or other search tools, and offers no exclusions or alternative routing.

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