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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds a genuinely useful non-obvious behavior: omitting the keyword yields trending/popular searches instead of an error. No rate-limit or result-shape detail, but that is minor here.

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?

Two sentences, zero filler, and the core identity (site typeahead) is front-loaded ahead of the fallback behavior. Nothing needs trimming.

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, and the description covers the key behavioral edge case. It could briefly clarify the required-vs-optional keyword discrepancy, which is the one thing an agent must resolve before calling.

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 the Limit default/cap is documented there, so the baseline is 3. The description's claim that keyword is optional adds value, but it conflicts with the schema, which lists Keyword as required — an agent that omits it may hit validation failure despite the description's promise.

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 ('search-suggestions/autocomplete for a partial keyword') and anchors it to the site's own typeahead behavior. This cleanly separates it from the sibling goldin_search, which returns full results rather than suggestions.

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 'typeahead for a partial keyword' framing makes the use case clear, and it explicitly describes the no-keyword case (trending searches). It does not name goldin_search as the alternative for full searches, so routing is implied rather than stated.

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