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

With no annotations, the description carries the full burden. It adds a useful behavioral note about billing (1 credit per call) and the verb 'gets' implies a read-only operation. However, it does not disclose what the returned metainfo includes, any authentication requirements, or potential side effects, which is a significant gap.

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 a single sentence, front-loaded with the core purpose, and the billing note is useful. The leading '**Object**' is unnecessary and slightly distracting, but overall the description is concise and to the point.

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?

Given the lack of an output schema, the description should explain what 'metainfo' encompasses or that it returns all available metadata fields. It also does not address the relationship to the specific sibling getters, leaving the tool's coverage ambiguous. Simple as it is, the description is insufficient for an agent to predict the return value or decide between this and the siblings.

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 input schema provides 100% coverage for the single parameter 'id', including an example and a regex pattern. The description adds no additional parameter semantics, so the baseline score of 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?

The description clearly states the tool retrieves metainfo from a video, using a specific verb ('Gets') and resource. However, it does not explicitly distinguish itself from sibling tools like get_info_title or get_info_duration, which also fetch video metadata, making the scope ('metainfo') somewhat ambiguous.

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 provided on when to use this tool versus the more specific sibling tools (e.g., get_info_title, get_info_duration). The description mentions billing but does not clarify whether this tool returns all metadata at once or if siblings should be preferred for single fields.

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