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

Annotations already declare readOnly, idempotent, openWorld, and non-destructive, so the safety profile is covered. The description adds 'bounded', hinting at a result cap, but says nothing about pagination behavior via cursor, whether the limit default is enforced, or the authentication implications of _apiKey that the annotations cannot express.

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 tight sentences, front-loaded with the resource and the returned fields, with the analytical purpose appended. 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?

With no output schema, enumerating the returned fields is genuinely valuable and largely fills that gap for a 7-parameter read tool. The remaining shortfall is filter semantics (type, success) and pagination expectations, which the description leaves to the schema and annotations.

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 coverage is 71% (limit, cursor, _apiKey, begin_time, end_time are documented), so baseline is 3. The description adds no meaning on the two undocumented filters, 'type' and 'success' — in fact 'type' and 'status' appear in the description only as returned fields, leaving the agent to infer that 'type' is also a filter.

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 ('Return') and resource ('Recurly payment transactions') and enumerates the fields surfaced, so the agent knows exactly what it gets. It does not explicitly contrast itself with recurly_list_accounts/invoices/subscriptions, though the distinct resource name makes the separation reasonably clear.

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?

'Answers which charges, refunds, and verifications succeeded or failed' implies the investigative use case, but there is no explicit when-to-use guidance, no exclusion rules, and no pointer to a sibling tool for adjacent needs.

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