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

Annotations already declare readOnlyHint=true and openWorldHint=true, covering the safety profile. The description adds useful cost context ('Free (0 credits)'), but does not describe return format, rate limits, authentication needs, or what 'usage' includes. With annotations present, this is adequate but shallow.

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 very short and front-loaded, with no wasted words. However, the first sentence merely restates the title, and the second is a cost note. It is concise but minimally informative.

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 is simple and annotations cover read-only behavior, but there is no output schema and the description does not explain what the usage result contains. For a tool named 'usage', an agent can infer some meaning, but the description stops short of describing return values or scope.

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 zero parameters, so there are no parameter semantics for the description to clarify. Per the baseline for parameterless tools, this score is appropriate. The description need not document any arguments.

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 gives a vague sense of purpose: retrieving the user's monthly usage. It does not state a specific verb or distinguish itself from the many sibling Instagram tools, and it largely repeats the title. An agent can infer the general area but not the exact resource returned.

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 such as instagram_check or instagram_insights. It mentions cost ('Free (0 credits)') but does not explain context, prerequisites, or exclusions. The description offers no usage decision support.

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