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

With no annotations provided, the description carries the full burden of behavioral disclosure. It reveals a key behavior: inaccessible private-space graphs are hidden from the results, indicating caller-aware filtering. This goes beyond the basic list action and is useful for understanding the tool's output.

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?

The description is a single, well-constructed sentence with a parenthetical clarification. It is front-loaded and every word adds meaning, with no redundancy or fluff. Ideal conciseness for the tool's simplicity.

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 0-param, no-output-schema list tool, the description is complete. It states what is listed, the filter behavior, and implies the return value (the list of graphs). No additional details are necessary for the agent to use this tool effectively.

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?

The input schema has zero parameters and 100% coverage, and the 0-param baseline is 4. The description does not need to elaborate on parameters since there are none, and it correctly focuses on the tool's purpose and behavior.

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?

The description clearly states the action (List) and the resource (registered named graphs), and it includes a specific scope qualifier: visible to the caller, with private-space graphs hidden. This distinguishes it from sibling list tools like brainkb_list_spaces or brainkb_list_users.

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 description implies when to use this tool (to discover graphs the caller can access) but does not explicitly state alternatives or exclusions. The visibility qualifier gives some contextual guidance, but there is no explicit 'use this instead of X' or conditions for when not to use it.

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