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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds genuinely useful context with 'append-only,' signaling an immutable historical record rather than a mutable balance, but says nothing about pagination, result volume, or ordering beyond what the schema shows.

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 with the purpose front-loaded and no wasted words. The REST endpoint reference is a mild redundancy but can aid doc cross-referencing.

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?

There is no output schema, so the description would ideally hint at what a ledger entry contains, but for a simple filtered read with a fully documented parameter set the omission is tolerable. It is minimally complete rather than richly so.

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%, so all five parameters (limit, cursor, currency, entry_type, customer_id) are already documented in the schema. The description adds no filter semantics or value examples beyond that, which is the expected baseline when the schema does the work.

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 ('Get the append-only credit ledger for a customer') and the 'append-only' qualifier implicitly distinguishes it from the sibling orb_get_customer_credits. It does not explicitly name that sibling or contrast the two, so it falls short of full differentiation.

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?

No guidance on when to use this versus orb_get_customer_credits or orb_get_customer_costs, and no stated prerequisites or exclusions. Usage must be inferred entirely from the tool name and resource noun.

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