Get disk usage and quota

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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), so the bar is lower. The description still adds real value beyond them: '0 = unlimited' decodes a sentinel quota value, grace-period status is disclosed as conditional, and 'refreshed hourly by MXroute' tells the agent the data's freshness, which prevents it from treating results as real-time.

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?

A single sentence that front-loads the primary return ('overall disk usage') and then details the fields. No filler or repetition of the title.

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?

With no output schema, the description carries the full burden of describing return values, and it does so thoroughly — all key fields, the unlimited sentinel, category breakdown, and grace-period condition. Nothing an agent needs in order to call this zero-argument tool correctly is missing.

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?

Zero parameters, so there is nothing to document and the baseline of 4 applies. The description correctly focuses on output content instead.

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 and resource ('Returns the account's overall disk usage') and enumerates exactly what comes back: bytes used, quota limit, percent used, category breakdown, grace-period status. The word 'overall' implicitly separates it from the per-mailbox get_email_usage sibling, but no sibling is named, so differentiation is inferred rather than stated.

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 explicit when-to-use statement, no prerequisites, and no reference to alternatives such as get_email_usage or list_packages. Usage is only implied by the tool's name and content.

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