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

With readOnlyHint=true already covering the safety profile, the description still adds real behavioral context: the default compact projection, what fields that includes, and the full=true switch for every setting. It also names the underlying endpoint, which aids traceability. Return format is sketched but pagination behavior is left to the schema.

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?

Front-loaded single sentence with the core action first, then the default-vs-full distinction and the endpoint tag. The long parenthetical field list is dense but each item earns its place by previewing the return shape; no filler sentences.

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?

No output schema exists, and the description compensates by enumerating the compact return fields and the full=true alternative, which is exactly what an agent needs to interpret results. Pagination and search semantics are left entirely to the schema, a minor remaining gap for a 4-parameter list tool.

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 the schema already documents full, page, search and per_page, making 3 the baseline. The description reinforces the meaning of full (compact vs every setting) and partly enumerates the compact result, but adds no syntax or semantics for search/page/per_page beyond what the schema provides.

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+resource with scope ('List the CDN pull zones on the account'), and the plural 'list' clearly separates it from the sibling bunny_get_pull_zone. An agent can select it without opening 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?

Usage is only implied: 'List ... on the account' suggests bulk retrieval, and full=true is framed as an option, but the description never states when to choose this over bunny_get_pull_zone or how pagination/search interact. No explicit when/when-not guidance.

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