get_library_metadata_by_ids_subtitles

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds one useful behavioral detail: if no URL is provided, subtitle contents must be in the post body. It does not contradict the annotations, but it omits other behavioral context such as whether this fetches metadata or actual subtitle file content.

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 short and front-loaded with the core purpose, followed by the endpoint and a compact argument list. No filler or redundant prose appears, though some argument descriptions could be more meaningful without hurting conciseness.

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 an 8-parameter tool with no schema descriptions, the description is too sparse to fully orient an agent. It does not clarify acceptable values for format, forced, or hearing_impaired, how media_item_id relates to ids, or when the URL/post-body path should be chosen. The output schema reduces the need to describe return values, but the input semantics remain incomplete.

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 0%, so the description must compensate. It does name every parameter and gives a few useful hints (e.g., language code, title filter, URL fallback to post body), but several entries are tautological or unhelpful: 'format: The format', 'forced: The forced', and 'hearing_impaired: The hearingImpaired' add no real meaning.

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 begins with a direct verb and resource: 'Get subtitles.' and includes the endpoint path, making the basic operation clear. However, it gives no detail about what kind of subtitles, for which media, or how it differs from similarly named sibling tools like get_library_metadata_by_ids_file or get_by_transcode_type_transcode_universal_subtitles.

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?

There is no guidance about when to use this tool versus alternatives. The description simply restates the operation and lists arguments, with no mention of prerequisites, use cases, or exclusions. An agent must guess which of the many metadata/subtitle-related siblings is appropriate.

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