Account status — credit balance and usage (free)

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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. The description adds genuinely non-redundant context: it is free and never bills credits, and it authenticates via the connector sign-in or X-API-Key when self-hosted. It doesn't say how many 'recent transactions' are returned or what happens with an invalid key.

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?

Three short sentences, front-loaded with the returned fields and followed by the two facts an agent most needs (no billing, auth method). No filler or restatement 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 burden of describing return values and does so by listing the five data points. Auth and cost are covered; the only gaps are the size/window of 'recent transactions' and error behavior for an unauthenticated call.

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 and the schema is empty, so there is no parameter semantics to document; a baseline of 4 applies. The description correctly signals that no inputs are needed by framing the call as a pure account read.

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 ('Check your MyMedi-AI account') and enumerates exactly what comes back: credit balance, USD equivalent, transaction count, recent transactions, last activity. That enumeration distinguishes it from sibling tools like buy_credits, which mutates rather than reports.

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?

Usage is implied by the name and the 'check your account' phrasing, and 'Free — never bills credits' implicitly steers agents away from buy_credits for balance inquiries. However, there is no explicit when-to-use/when-not-to-use statement or named alternative.

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