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

Annotations already establish the tool as mutating, non-destructive, and idempotent. The description adds valuable batch-specific behavior: attributes are REPLACED not merged, and og:image fallback is skipped. These are important edge-case disclosures that go beyond the 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 two sentences with no redundancy. The first sentence states purpose and scope; the second sentence covers batch-specific gotchas. 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 tool with 15 parameters, batch behavior, and no output schema, the description covers the most critical caveats: how to batch, replacement semantics, and the og:image fallback skip. It does not mention error handling or return format, but the schema and annotations are already rich, and the description provides enough to use the tool safely.

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 schema already covers all 15 parameters with detailed descriptions (100% coverage), so the baseline is 3. The description adds meaningful nuance by clarifying that the 'attributes' parameter behaves differently in batch mode (replaced, not merged), which is not obvious from the schema's 'Merge into existing attributes'.

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 'Edit fields on one or more saved items,' which is a specific verb+resource+scope. It clearly distinguishes itself from siblings like add_item, update_collection, and update_price by focusing on editing existing items, and further specifies single vs. batch updates.

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 provides clear context for when to use this tool (editing saved items) and explains batch vs. single usage. It does not explicitly name alternatives (e.g., 'use add_item to create'), but the verb 'edit' and 'saved items' makes the intended use unambiguous.

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