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

readOnlyHint=true already conveys the non-mutating profile, lowering the bar for the description. The text adds two real behavioral details — cursor pagination and the canonical 'Recurly: GET /accounts' endpoint — but does not disclose rate limits or response-shape behavior. That lands it at mid-range for an annotated read tool.

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 sentences with zero filler: purpose first, capabilities second, canonical endpoint last. Every sentence earns its place.

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 read-only list with 0 required params and a fully documented schema, the description covers the invocation essentials and even announces pagination and filtering. With no output schema present, a note on the return shape would make it fully complete.

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 100%, so all 8 optional parameters (sort, order, email, limit, begin_time, end_time, past_due, subscriber) already carry descriptions; the baseline is 3. The description's 'filtering' mention only echoes the schema's filter params and adds no format or syntax semantics.

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?

Names a specific verb and resource — 'List customer accounts on the site' — with an explicit scope. The plural accounts resource and the List verb distinguish it from recurly_get_account and from the list_invoices/list_plans/list_subscriptions siblings without needing to open the schema.

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 verb and sibling set make the use case inferable (enumerate accounts rather than fetch one), but no alternative tool is named and no when-not-to-use condition appears. This is implied usage, not explicit routing guidance.

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