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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is known. The description usefully adds the auth prerequisite (session_token from auth_verify_otp) and the scope/content of the ledger data returned, but says nothing about pagination, ledger window, or rate limits for what may be a large ledger listing.

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 tight sentences with the core purpose front-loaded and the prerequisite second. Efficient, though the second sentence largely restates what the schema already encodes about session_token.

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 returns, and it does so at a high level: balance plus recent topups, debits, and refunds. For a one-parameter read tool this is nearly complete, with only ledger scope/window left unspecified.

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?

Schema description coverage is 100% for the single parameter, and the schema already explains session_token's origin and pattern. The description's mention of the token adds provenance but no new format or constraint meaning beyond the schema.

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 specific verb and resource: checks the signed-in account's FLINT Scout credit balance plus recent ledger activity, and enumerates the activity kinds (topups, debits, refunds). It is clearly distinct from the mutation sibling scout_credits_topup, but it does not explicitly name that sibling, so sibling differentiation is implied 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?

Usage is implied (check the balance of a signed-in account) and the dependency on session_token from auth_verify_otp establishes a prerequisite. However, there is no explicit when-to-use vs. when-not guidance, nor a pointer to scout_credits_topup for adding credits, so an agent must infer routing.

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