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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds value by specifying the exact return payload (full ItemData with system blob fields), which is useful behavioral context beyond the annotations. However, it doesn't disclose potential error conditions (e.g., what happens if the itemId doesn't exist) or any rate limits, but for a simple read operation with strong annotations, this is adequate.

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 a single, information-dense sentence that front-loads the core purpose ('Get full ItemData for a single world item') and then enumerates the return fields. Every word earns its place; there is no fluff or repetition. The parenthetical '(read-side)' adds a useful nuance about the folder name being the read-side representation, which is valuable without being verbose.

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 single-item read tool with one parameter, strong annotations (readOnly, idempotent, non-destructive), and no output schema, the description is nearly complete. It tells the agent what it returns, where the ID comes from, and the annotations cover safety. The only minor gap is the lack of explicit error behavior (e.g., not-found handling), but that is not critical for a read operation. The description is sufficient for an agent to select and invoke the 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?

Schema description coverage is 100%: the only parameter, itemId, is described as 'World item ID (from world-item-filter).' The description adds a small amount of context by clarifying that the ID comes from world-item-filter, which is helpful for the agent to know how to obtain it. However, the description doesn't add much beyond the schema's own description, so the baseline 3 is appropriate.

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 clearly states the tool's purpose: retrieving full ItemData for a single world item. It enumerates the specific fields returned (id, uuid, name, type, image, folder NAME, and the complete system blob with examples), which distinguishes it from sibling tools like world-item-filter (which lists/filters items) and world-item-update (which modifies items). The verb 'Get' plus the resource 'world item' is specific and unambiguous.

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 is the read tool for a single world item, and the parameter description 'World item ID (from world-item-filter)' provides a clear source for the required ID, effectively guiding the agent to first use world-item-filter to obtain the ID. However, it does not explicitly state when to use this tool versus alternatives like world-item-filter or item-get, nor does it mention exclusions (e.g., 'use world-item-filter to list items'). The context is clear but not fully explicit.

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