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

The readOnlyHint annotation already establishes that this is a safe read, so the description's burden is lower. It adds that results can be scoped by parent and maps to GET /api/v1/folders, but says nothing about pagination behavior or what a result set contains.

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 clauses, front-loaded with the purpose and zero filler. The trailing REST-endpoint mapping is marginally useful for parity checks but not essential.

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?

Read-only safety is covered by annotations and all three params are schema-documented, so the core is intact. With no output schema, a note on the shape of the returned folder list and how pagination interacts with parent filtering would have closed the remaining gap.

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 page, per_page, and parent_id are all documented in the schema, including the 'root' literal. The description adds only the 'optionally' qualifier on parent filtering, meeting the baseline for schema-covered parameters.

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 and resource ('List media library folders') plus the filtering capability, which is enough to distinguish it from create_folder/delete_folder/update_folder. It stops short of explicitly contrasting with the closely related get_folder (single item) sibling.

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?

'Optionally filtered by parent' implies the browse-vs-drill-down use case, and the REST endpoint mapping hints at read semantics. However, there is no explicit when-to-use guidance or statement of when get_folder would be preferred over this list call.

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