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

Annotations already declare readOnlyHint=true, so the safe-read profile is covered structurally, and the GET endpoint citation reinforces it. The description adds nothing about pagination behavior (cursor semantics), volume, or rate limits, so it clears the lower annotated-bar only modestly.

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 fragments, front-loaded with the core action and free of filler. The endpoint citation is compact and informative, though the phrasing is telegraphic rather than polished prose.

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 read-only list tool with full schema coverage and annotations, the description covers the essentials. It omits any note on pagination flow or how this differs from the general transaction-listing sibling, which is the main remaining gap given no output schema exists.

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 three parameters (limit, cursor, account_id) are already documented in the schema. "Filter by account" merely echoes account_id without adding format or syntax detail, so the baseline 3 applies.

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 ("List declined transactions") and even maps it to the underlying endpoint GET /declined_transactions. It implicitly separates itself from increase_list_transactions and increase_list_pending_transactions via the "declined" qualifier, but never explicitly distinguishes the three.

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?

"Filter by account" gives a hint about a common narrowing use, so usage is implied. However, with siblings like increase_list_transactions and increase_list_pending_transactions in the namespace, the description never says when to pick this one instead — no exclusions or alternative routing.

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