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

Annotations already declare readOnly/openWorld/idempotent/non-destructive, so the safety profile is covered. The description's one value-add is "0.5 credit", a cost signal not present in annotations — genuinely useful for budget-aware agents. It says nothing about return shape (a list of suggestion strings) or rate limits, so it stays at a moderate score rather than higher.

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 terse fragments with no filler, but this is brevity by omission rather than disciplined front-loading — the cost note is present while the actual behavior is not. Short is good here, yet the reader still has to open the schema and infer the semantics.

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 3 fully-documented params and rich annotations, the structural scaffolding is in place, but the description leaves the core question unanswered: what does it return and why choose it over search? For a tool whose output is the entire point (a suggestion list), saying only "Query suggestions" is thin.

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 q, country, and language are all documented in the schema itself, including the useful note that language does not change country. The description adds no parameter meaning beyond that, so the baseline of 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?

"Query suggestions" restates the title (Google Autocomplete) rather than describing an action or output: it never says it returns Google's autocomplete completions for a partial query. There is no verb and no differentiation from siblings like search or answer, which also accept a query and return results.

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?

No guidance at all on when to use this versus search, answer, or ai_mode — an agent has no way to know this is for expanding/completing a partial query rather than retrieving results. The only non-schema information is a cost note, not a usage condition.

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