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

Annotations already establish the mutation profile (readOnlyHint=false, destructiveHint=false, idempotentHint=false, openWorldHint=false), and the description adds real behavioral context beyond them: the cover/page linkage requirement, the null-to-restore semantics, and that the cover renders the page's live version. It omits partial-update semantics (whether unspecified fields are left untouched) and any permission requirements.

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?

Four short sentences, front-loaded with the primary action and followed by the cover-specific rules in priority order. The null-reset sentence partially duplicates the schema's own cover_proposal_id description, which is a minor redundancy but not wasted space.

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 four-parameter mutation tool with no output schema and reasonable annotation coverage, the description supplies the field list, the cover constraint, and the reset behavior. It stops short of stating permission requirements or whether untouched fields are preserved, which are the only notable 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 only 25%, with just cover_proposal_id documented inline, so the description does meaningful compensating work by naming the three mutable fields (name, introduction, cover) and reiterating the null-reset behavior for the cover. Only folder_id and the fine-grained format limits remain unexplained by both sources.

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 concrete verb and resource ('Change a folder's name, introduction or cover') and enumerates the mutable fields, so the agent immediately knows this is a partial-update tool for folders. It does not explicitly distinguish itself from siblings like create_folder or list_folders, but the mutation scope is unmistakable.

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 conditional rules rather than usage routing: the cover must be a page inside this folder shared through the folder link, and setting cover_proposal_id to null restores the generated index. There is no explicit statement of when to prefer this tool over alternatives, but the constraints imply the intended usage context.

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