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

With no annotations provided, the description carries the burden of behavioral disclosure. It usefully states that the return value is a localized string and that billing is 1 credit per call. It does not mention authentication requirements, rate limits, or error behavior, so several gaps remain.

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 extremely short and front-loads the return type and resource. Every fragment serves a purpose: return type, grouping, and billing. There is no unnecessary prose.

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 simple one-parameter field getter with complete schema coverage and no output schema, the description provides enough to call it correctly: it says what is returned and the per-call cost. Usage versus alternatives is missing, but the core behavioral and output context is present.

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 schema describes the single required id parameter with full coverage, including a YouTube ID format example. The description adds no additional parameter meaning beyond the schema. Baseline 3 is appropriate because the schema already handles parameter documentation.

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 clearly identifies the returned resource as the localized video description and labels it as part of Specific video Info. This distinguishes it from sibling field getters such as get_info_title and get_info_duration by the field name alone. It does not, however, explicitly contrast itself with get_info or other alternatives.

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 provides no guidance on when to use this tool instead of get_info or another sibling. It mentions grouping and billing cost, but not the conditions under which an agent should call this specific field getter. Usage context is only implied by the tool name.

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