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

Beyond the annotations (destructiveHint, idempotentHint, openWorldHint) it discloses that login/organizer authority is required, that a PUBLIC visibility change is irreversible ('PUBLIC公开后无法收回别人所见'), that preview is a true dry-run, and that per-item failures are reported in 'failed'. This is exactly the revocation/auth/failure context structured fields cannot carry.

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?

Dense and front-loaded: authority tag first, then ids source, then scope, then the preview workflow, then the irreversibility warning, then sibling routing. Every clause carries load with no filler.

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 mutating batch tool with no output schema, the description covers authority, id source, batch limits, preview commit path, irreversible effects, per-item failure reporting, and alternative tools. Nothing an agent needs to invoke it correctly is missing.

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 preview, activityRef and the 50-item cross-activity items array. The description restates the preview-first and 50-item/cross-activity semantics rather than adding syntax or constraints absent from the schema, so the 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 (改名/可见性) plus resource (activity materials), and adds scope: batch, cross-activity (可跨场), up to 50 items. It also names the siblings it is not — upload via add_activity_material/prepare_activity_material_upload and delete via remove_activity_material — so the agent can distinguish it without opening any 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?

Explicit workflow and alternatives: fetch ids with list_activity_materials, run preview=true first then omit preview to commit, and route upload/delete to their respective tools. Both the when and the when-not are stated, leaving nothing to inference.

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