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

Annotations already declare readOnlyHint:true, idempotentHint:true, destructiveHint:false, so the description does not need to repeat that. It adds value by describing the returned fields (id, label, is_default) and the special meaning of is_default (when only one base), which is behavioral context beyond the annotations. A small gap: it doesn't mention whether pagination or sorting applies, but for a list likely trivial. Score 4.

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 concise sentences: first states the core functionality, second adds crucial context about the is_default flag and account parameter usage across other tools. Every sentence adds value, no redundancy, front-loaded with the primary purpose. Perfectly structured for an agent.

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?

The tool has no parameters and no output schema, so the description carries full burden. It covers what is returned (id, label, is_default), the meaning of is_default, and the implications for sibling tools. For a simple list tool with no input, this is complete. The presence of sibling context (kb_* tools) makes the cross-reference to 'account' useful.

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?

There are zero parameters and schema coverage is 100% (no params), so description has nothing to add. Baseline for 0 params is 4, and the description does mention that other tools accept an optional `account` parameter (related to this tool), but that's about other tools. For this tool itself, no parameter semantics needed. Score 4.

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?

Clear verb-object: 'Lista as bases de conhecimento conectadas' (lists connected knowledge bases). It explicitly states returns id, label, and is_default flag, and it distinguishes from siblings (kb_list_documents, kb_search, etc.) by focusing on the account/list of knowledge bases.

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 explains when to use: to discover if there is a single account (no need to pass 'account' in other tools) or multiple (then pass an optional 'account' id/label). This guides the agent on when to call this tool and how the result affects usage of other kb_* tools, providing clear when-to-use context.

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