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

With no annotations, the description carries the transparency burden. It does disclose the output type, localization behavior, and per-call billing cost, but it does not describe read-only guarantees, practical id requirement, or error behavior.

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 very short and front-loads the essential output type and value. All fragments (string output, localized title, group, billing) earn their place, but the lack of a complete syntactical statement makes it slightly less structured than ideal.

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 getter, the description covers return type and billing, and the schema covers the input. However, with many get_info_* siblings and no output schema, the missing usage guidance leaves the description 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?

The sole parameter id is already fully documented in the input schema with format, example, and regex. The description adds no additional parameter context, so it meets the schema-covered baseline of 3.

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 identifies the tool's return value as 'the localized video title,' and the name/title make clear it fetches the title for a video. It is not a tautology, and the 'Specific video Info' grouping helps set it apart from broader siblings, though no explicit verb like 'retrieves' is used.

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?

No guidance is given about when to call this instead of get_info or the other get_info_* field tools. The description only states the group and billing, neither of which explains selection criteria or alternatives.

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