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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so repeating 'Read-only' adds no new information. The only extra behavioral detail is the 'this month' aggregation window, which is useful but thin. It doesn't mention freshness, limits on period, or what happens for accounts with no activity.

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 front-loaded sentence carries the trigger, the returned data, and the safety profile. There is no filler and nothing an agent must read past to act.

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 zero parameters, an output schema that documents the return shape, and annotations covering the safety profile, the description supplies everything else the agent needs: what the tool measures and the time window. Nothing material is missing for a call that takes no arguments.

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 takes zero parameters, so there are no parameter semantics to explain and the baseline of 4 applies. Nothing in the description misleads about inputs, and additionalProperties: false is consistent with a no-arg call.

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 names a specific resource (account allowance usage) and enumerates the two components returned: dynamic codes created against the limit and scans this month. That clearly separates it from scan-total siblings like get_total_scans or get_qrcode_scans, though it doesn't name a specific alternative tool by name.

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?

It gives an explicit trigger condition — 'when the user asks how much of their allowance they have used' — which is exactly the kind of routing signal an agent needs. It stops short of naming when to use get_account_entitlements or get_account_overview instead, so there is no explicit exclusion set.

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