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

Annotations already declare readOnly, idempotent and non-destructive, so the safety profile is covered. The description adds genuinely useful behavior beyond that — records are append-only (immutable) and results are ordered newest first — but says nothing about pagination mechanics, the default page size, or whether a cursor expires.

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?

A single tightly written sentence, front-loaded with the resource and carrying two useful qualifiers with zero filler. Nothing is wasted.

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?

For a simple two-parameter list tool with no output schema, the description establishes purpose and ordering but omits paging guidance and any hint of what a transaction record contains. Adequate to call it, not quite enough to call it correctly on a multi-page history.

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 0%, so both parameters (limit, cursor) arrive undocumented and the description never mentions either. The names are conventional, but there is no statement of the default limit, the 1–100 range, or how to obtain and reuse a cursor, leaving the description to compensate for the gap and not doing so.

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 ('Read your ... credit history') plus two scoping facts: the history is append-only and returned newest first. It is clearly distinguishable from the balance-oriented sibling get_credit_balance, though it never names that sibling explicitly.

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 only implied: 'history' versus a point-in-time balance suggests when to pick this over get_credit_balance, but the description gives no explicit when-to-use or when-not rule and does not mention the topup/transaction siblings.

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