Look up catalog items

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

Annotations already declare readOnly, idempotent and non-destructive, so 'Changes nothing' is largely redundant. The genuinely additive detail is the 'Up to 100 item IDs' batch ceiling and the accepted country/language formats, which are behavioral constraints not present in the annotations or schema.

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?

Very short and purpose-first, which is good, but the second paragraph is a dangling fragment with no subject ('country e.g. ... language e.g. ...') that reads as a stripped schema hint rather than a sentence. It could be reformatted as one clear sentence about accepted formats and the 100-ID cap.

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 6-parameter tool with zero schema coverage and no output schema, the definition covers only the three required parameters. It never explains when catalog_id or ad_account_id must be supplied or what catalog_type='RETAIL' means, and it doesn't distinguish this tool from the batch item siblings, leaving real ambiguity.

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 carries the burden. It clarifies item_ids (feed id column, max 100), country ('GB') and language ('en-GB'/'EN') formats, but leaves catalog_id, catalog_type (default RETAIL) and ad_account_id completely unexplained, which is half the parameter set.

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?

States a specific verb and resource ('Look up catalog items by item ID') and adds the useful disambiguation that the ID is the feed's 'id column'. It does not name the closely related siblings (get_catalog_items_batch, batch_catalog_items), so an agent must infer which lookup variant to use.

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?

There is no when-to-use guidance and no exclusions. With several sibling tools operating over the same catalog item space (batch_catalog_items, get_catalog_items_batch, list_item_issues), the description never says when this single-batch lookup is preferred over those alternatives.

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