hey_cache_status

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

The description explicitly states 'Read-only with no side effects,' reinforcing the readOnlyHint annotation. It adds verbal confirmation and context about side effects beyond the annotation.

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 front-load the main purpose and provide additional context. 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?

Without an output schema, the description adequately explains what the tool returns (message counts, cache age, storage estimate). It covers the main purpose and optional parameter, but could briefly mention the return format or structure.

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 100% coverage and includes description for the optional folder parameter. The description adds value by explaining the purpose of the folder parameter: 'query a specific folder for message/unread counts.'

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 specifies a clear action: get cache statistics, listing specific data points (message counts, cache age, storage estimate). This distinguishes it from sibling tools which generally deal with emails, labels, or actions, not cache status.

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 provides explicit guidance: 'Use before force_refresh decisions.' It sets a clear context but does not mention when not to use or list alternatives. Since the tool is unique among siblings, this is acceptable.

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