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

Annotations declare destructiveHint=true and readOnlyHint=false, yet the description says 'List recent card data changes', which strongly implies a read-only operation. The description does not disclose any destructive behavior and directly contradicts the annotations, creating a serious risk that an agent misjudges the tool's side effects.

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?

The description is compact and front-loaded: the first sentence states the action and resource, and the second supplies a natural-language use case. The phrase 'what changed recently?' is somewhat redundant with 'recent' and 'changes', but it still helps an agent recognize matching queries.

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?

The tool has no output schema, and the description only says 'list' without describing the shape or content of results beyond the examples of change types. More importantly, the destructive annotation is left unexplained, so an agent cannot tell whether invoking this tool mutates data. This is a significant completeness gap.

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 input schema already provides complete descriptions for all three parameters (days, limit, card_id), including defaults and filtering semantics. The description adds little beyond the word 'recent', but because schema coverage is 100%, no compensatory parameter detail is required.

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 opens with the action 'List recent card data changes' and enumerates the domain via examples such as welcome bonus updates, fee changes, and multiplier edits. This clearly identifies the card-data-changes resource and distinguishes it from sibling tools like cards_list_cards or cards_analyze_spending.

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?

The description explicitly says it is useful for 'what changed recently?' queries, which gives an agent a concrete trigger for choosing this tool. However, it does not provide when-not-to-use guidance or name alternative tools, so it misses the explicit exclusions needed for a 5.

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