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

The annotations already declare readOnlyHint and destructiveHint, and the description adds useful operational context: a per-call cost of $0.10 and the need for an API key. These are behavioral details beyond the structured annotations and help the agent anticipate side effects and prerequisites. No contradiction with annotations.

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 extremely concise, with one clause for purpose and a parenthetical for operational constraints. Both sentences earn their place, and the information is front-loaded with minimal waste.

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 is simple with one parameter and has an output schema, so a short description can be adequate. However, it lacks usage guidance relative to siblings and leaves the semantics of the query parameter under-specified, which creates some gaps for correct invocation.

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%, and the query parameter has no description beyond its name and type. The phrase 'keyword search' implies that query is the search term, but the description does not clarify requiredness, matching behavior, formatting, or the effect of additionalProperties. It only partially compensates for the schema gap.

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 states a specific verb and resource: 'Keyword search over transactions.' It clearly indicates the operation and target, but it does not explicitly contrast with related siblings like get_transactions or get_person_transactions, 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 is given about when to use this tool versus alternatives. The description mentions cost and API key requirements, but not the conditions under which an agent should pick search_transactions over get_transactions or other search tools.

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