memory_stats

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

With no annotations provided, the description must carry all behavioral disclosure. It only states the tool reports the index state, but does not indicate side effects (likely read-only), the format of the output, or any resource implications. This falls short for a zero-parameter tool where the description is the only source of information.

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 extremely concise (one sentence) and front-loaded, efficiently stating the core purpose. While it is minimal, it avoids unnecessary fluff, which is appropriate for a simple tool.

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, no output schema, and no annotations. The description provides only a high-level purpose without explaining what the returned stats look like, how they might be interpreted, or when to rely on them. This is insufficient for an agent to gauge the tool's usefulness or integrate its results meaningfully.

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 tool has zero parameters, so the baseline is 4. The description does not need to explain parameters since none exist, and the schema is trivially covered. No additional param semantics are required.

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 states the tool reports the state of the local mail index, which is a clear purpose and distinct from siblings like list_messages or search_mail. However, it is generic and does not specify what 'state' entails (e.g., size, sync status, last updated), so it only partly conveys the function.

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?

There is no guidance on when to use this tool versus alternatives. For a diagnostic tool, it would be helpful to know if it is meant for troubleshooting or monitoring, but the description offers no context or exclusions.

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