get_email_stats

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

The readOnlyHint annotation already indicates a safe read operation. The description adds context about the nature of the returned data (aggregate counts, sample). It does not disclose potential side effects, but none are expected for a read-only tool, and the annotation covers that. The description provides useful context 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?

The description is three sentences, front-loaded with the main purpose, followed by usage guidance. Every sentence earns its place with no redundancy.

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 simple read-only tool with no output schema, the description adequately covers what is returned (folder counts, unread counts, sample), when to use it, and how it relates to sibling tools. The parameters are self-explanatory via schema, and the description gives enough context for an agent to invoke it correctly.

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?

Schema description coverage is 100% with clear parameter descriptions ('Trailing days window' and 'Maximum messages to sample'). The tool description does not add further semantic detail about parameters, so it stays at the baseline for schema-covered params.

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 tool returns aggregate mailbox statistics (folder message counts, unread counts, analytics sample) with a specific verb and resource. It also distinguishes itself from siblings by naming get_email_analytics and get_volume_trends as alternatives for different needs.

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?

Explicit usage guidance is provided: 'Use for a quick mailbox health overview' and direct recommendations to prefer get_email_analytics for richer breakdowns and get_volume_trends for time-series data. This clearly tells an agent when to use this tool versus alternatives.

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