item_lookup

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

Without annotations, the description carries the full burden. It discloses the return fields (IDs, titles, categories, vault IDs) and the substring matching behavior, which is useful. However, it does not explicitly state that it is a read-only operation, nor does it mention any pagination or default behavior when query is omitted—though the schema covers limit.

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 two concise sentences, front-loaded with the primary action and resource. There is no redundant or filler content; every word contributes to understanding the tool's purpose and output.

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 search tool with fully documented parameters and no schema, the description provides key information: purpose, matching method, and returned fields. However, it does not explain behavior when query is omitted (which the schema implies returns all items) or any result ordering, leaving a small gap in completeness.

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%, so the baseline is 3. The description adds minimal semantic value beyond the schema: it reinforces that the query is a title substring filter and that the search is vault-scoped, but these are already in the schema descriptions.

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 states a specific action ('Search for items') with a precise resource ('1Password vault') and method ('by title substring'). It clearly distinguishes from siblings like item_list (which likely lists all items) and item_get (single item retrieval) by specifying substring search.

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 usage for finding items by title substring but does not explicitly state when to prefer this over item_list or other alternatives, nor does it give exclusions. It gives minimal context but lacks explicit 'use when' or 'instead of' guidance.

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