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

Annotations already cover read-only, idempotent, non-destructive behavior. The description adds useful context beyond that: it names the returned fields and explicitly calls out that a key is required, which helps the agent understand authentication needs without contradicting the annotations.

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 short sentences, zero filler. The key information is front-loaded, and the documentation link is appended without diluting the main purpose.

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?

Given the simple zero-parameter read-only nature, the description is nearly complete: it states what the tool returns and the authentication prerequisite. The only minor gap is leaving the term 'mite' undefined, though the docs link and sibling context mitigate that risk.

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?

With zero parameters, the schema has nothing to document, so the baseline is 4. The description appropriately notes that the key comes from context rather than as an input parameter, which is the only relevant parameter-related guidance needed.

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 identifies the resource: the 'mite' or account behind the current key, and lists what it exposes (wallet, level, accuracy, limits). It lacks an explicit verb like 'retrieve' or 'show', but the meaning is unambiguous and distinct enough from sibling tools.

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 implies the use case: check what account is associated with the current key. It states the prerequisite ('Needs a key') but does not explicitly compare against alternatives or say when not to use it, leaving some routing to inference.

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