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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint false, and openWorldHint false. The description adds that it finds stale pages, orphaned knowledge, and other issues, which is useful context about the diagnostic behavior and expected findings beyond the safety profile. It does not cover frequency or remediation, but with annotations covering safety, 4 is appropriate.

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?

Single sentence, front-loaded with the action and resource, then concrete examples. No wasted words.

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 zero-parameter, read-only diagnostic tool with rich annotations and no output schema, the description adequately explains what the tool does and what it looks for. It could specify whether the checks are advisory or whether it takes any action, but annotations already clarify read-only and idempotent behavior.

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 no parameters (0), so the baseline is 4 per rubric. The description does not need to explain parameters.

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 ('Run maintenance checks') and resource ('your brain'), and enumerates the issues it surfaces (stale pages, orphaned knowledge). It does not explicitly distinguish itself from sibling tools like brain_status, so a 4 rather than 5.

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 purpose implies when to use it (periodic maintenance/diagnostics), but there is no explicit when-to-use guidance, no alternatives named, and no exclusions. Implied usage only.

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