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

Annotations already cover readOnlyHint, idempotentHint and destructiveHint, so the burden is light. The description nonetheless adds a genuine behavioral trait not present in structured fields: this endpoint is excluded from visit metrics so typeahead traffic does not inflate analytics. That is real, non-obvious context, though it says nothing about rate limits or result shape.

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 short sentences, purpose front-loaded in the first word. The second sentence is a rhetorical justification rather than a fact statement, but it does carry a usable behavioral caveat and does not bloat the definition.

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?

For a simple one-parameter read-only tool with full schema coverage and no output schema, the description is close to adequate: purpose plus the metrics caveat. It still omits any indication of what the response contains or the expected call frequency, which matters for a typeahead endpoint.

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?

Only one parameter (q) with 100% schema description coverage — "O que já foi digitado" is already documented in the schema. The description adds no syntax, length or encoding detail beyond it, so the 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?

"Autocomplete" names the feature but not a specific verb+resource, and it does not state what it returns (a ranked list of query completions). A sibling named 'search' exists, yet nothing here separates suggest-typeahead behavior from full search, so an agent must infer the distinction.

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 when-to-use guidance and no mention of the 'search' sibling as an alternative. The description never says this is for incremental keystroke-time queries versus explicit user-initiated searches, leaving routing entirely to inference.

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