Find product categories

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

Annotations already declare readOnly/idempotent/non-destructive/openWorld, so the safety profile is covered. The description adds genuinely non-obvious behavior: `query` also returns the site's popular search phrases, and a `parent_id` listing includes brand shortcuts. It stops short of saying how many results come back or how deep the tree goes, so not a 5.

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-loaded with the core purpose, then the primary use case, then the mode distinctions. Three sentences with no filler; the final sentence is dense but each clause (top-level, parent_id, brand shortcuts) carries distinct information.

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 no output schema, the description does the work of explaining what comes back in each mode, which is the main risk area for this tool. Remaining gaps (result counts, tree depth, whether ids are site-specific) are minor for a two-param read-only lookup.

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 coverage is 100%, so the baseline would be 3, but the description adds meaning beyond the schema: it clarifies that `parent_id` values come from this same tool's output and that `query` output carries extra popular-search-phrase data. That extra linkage is useful routing information the schema alone does not convey.

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 (find/browse) and resource (Emalls category ids / category tree), and immediately contrasts the two operating modes. It also names the downstream sibling em_search, making it distinguishable from em_filters, em_product and the rest of the sibling set.

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?

Explicitly says when to use it: to obtain a `category_id` for em_search when the user names a product kind ("laptops", "fridges"). It also distinguishes the three invocation modes — with `query`, without `query`, and with `parent_id` — so an agent knows exactly which form to call.

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