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. The description adds that results are paginated and maps to GET /add_ons, which is useful context, but it says nothing about ordering, default page size, or response shape.

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 short sentences with zero filler and the purpose front-loaded. The API endpoint note is compact and earns its place as a reference, though it is slightly redundant with the tool name.

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, zero-required-parameter list tool with no output schema, the description covers the essentials, but it leaves the agent without any sense of what an add-on record contains or how results are ordered. Adequate but with clear gaps.

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 both page and per_page are fully documented in the schema itself. The word 'paginated' in the description only indirectly signals those parameters, adding no syntax or default-value detail beyond the schema. 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 (List) and resource (add-ons) and notes pagination, which is enough to distinguish it from sibling list tools like lago_list_coupons or lago_list_plans. It does not explicitly differentiate from those siblings, but the resource name is unambiguous.

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 gives no guidance on when to use this tool versus alternatives, no prerequisites, and no exclusions. Pagination is mentioned but not framed as a usage condition (e.g., when to iterate pages or how to size per_page).

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