create_library_metadata_by_id_posters

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

Annotations already mark the operation as non-read-only, idempotent, and non-destructive, and the description reinforces the write nature with 'Upload.' It adds only the procedural hint to consult GET/schema first, but says nothing about whether an existing poster is replaced, what payload format is expected, or what response to expect. No contradiction with annotations.

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?

The description is brief, front-loaded with the core purpose, and avoids fluff. The endpoint and args lines are somewhat redundant with the tool name and schema, but the overall size is appropriate and easy to scan.

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 two-parameter create call with an output schema, the description gives the essential operation and tells the agent how to discover the body contract. It is incomplete regarding poster-versus-art selection, expected payload format, whether a URL or binary file is required, and any permission constraints.

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?

The `id` parameter gets a generic but acceptable gloss, and `body` is described only as a request payload with a pointer to GET/schema for its fields. With schema description coverage at 0%, this is helpful for discovery but does not specify the actual structure, media encoding, or upload format.

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?

The description starts with 'Upload media art Poster,' a specific verb and resource, and the endpoint path clarifies the target object. It does not differentiate from the closely named sibling create_library_metadata_by_id_arts, so it stops short of full sibling distinction.

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 clearly implies the tool is used to upload a poster for a library item, and it advises reading the matching GET or /schema endpoint before constructing the body. However, it does not explicitly state when to prefer this over the arts sibling or exclude alternatives, leaving much of that decision to the tool name.

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