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

Annotations only cover readOnly/openWorld, but the description adds real behavioral context beyond them: the dual query/no-query behavior and the explicit warning that search_history is fixed default content, not a real per-caller history. That last disclosure prevents a genuine misinterpretation of the response.

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?

Three sentences, front-loaded with the core purpose, then the mode split, then the data caveat. No filler; each sentence 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?

An output schema exists so return values need not be explained, yet the description still volunteers the key response caveat about search_history. Complete for a single optional-parameter read tool.

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% and already documents the omit-for-trending behavior, so the baseline is 3. The description earns an extra point by specifying what a supplied query yields ('spelling-complete phrase suggestions and merchandised content results'), which is richer than the schema's terse note.

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 ('H&M's own search-box typeahead suggestions') and describes the two output modes, which cleanly separates it from the plain hm_search sibling. An agent can tell what this returns without opening the schema.

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 clear context for both invocation modes: supply a query for phrase suggestions, or omit/empty it for trending and popular searches. It does not, however, name the alternative tool (e.g. hm_search) or state when not to use this one, so it stops short of explicit routing.

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