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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so safety is covered; the description adds real behavioral context beyond that by disclosing that results branch into three catalog types (store/campaign/quote) with different shapes and a how_to_ask field that dictates the follow-up call. It does not mention pagination or auth needs, keeping it below a top score.

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?

Front-loads the core action and purpose in the first clause, then uses one tight sentence per catalog type. Every sentence carries distinct information about how to build the next call; nothing is restated from the schema or annotations.

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?

With an output schema present, the description need not explain return fields, and it correctly focuses on the interpretation an agent still needs: which catalog flavor was found and what payload shape to use downstream. It is nearly complete, missing only error/empty-result behavior.

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 all four parameters (vendor_id, query, limit, collection) are already documented; the description's detail about handles, variant_ids and recipes describes results rather than input parameters. It neither compensates for nor extends the schema, so baseline 3 applies.

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+resource ('Search a vendor's catalog') and adds the downstream reason ('so the offer can name exact products'), which separates it from haggl_list_vendors and haggl_search_discounts by making clear it reaches a single vendor's product inventory. It stops short of naming an alternative sibling explicitly, so it is clear but not sibling-differentiated by name.

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?

Gives the triggering context (needed when an offer must name exact products) and a concrete next step ('follow the how_to_ask field of the result'). It never states when NOT to use it or which sibling to prefer for a different need, so it is clear context without exclusions.

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