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

Annotations are absent, so the description carries full burden for behavioral transparency. It is a read-only operation, but the description does not explicitly state that it performs no side effects or modifications. It also does not disclose the return format or any error conditions, leaving the agent to infer behavior from the word 'get'.

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, using a single sentence to convey the core purpose, with additional metadata (group and billing) in a separate sentence. The placeholder syntax is a trivial waste of space but not a significant structural issue. It is appropriately front-loaded with the key value.

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 tool's simplicity (one parameter, high schema coverage), the description is adequately informative for basic use. However, it does not mention return type or units beyond pixels, and lacks guidance on potential errors or when the width might be unavailable (e.g., for live streams), which are relevant for a video info tool.

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 covers the only parameter 'id' with a description and example. The tool description does not add any additional parameter semantics beyond what the schema provides, which is acceptable for a single well-documented parameter under high schema coverage.

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 that this tool returns the maximum width in pixels of the encoded video content, using a specific noun ('width') and resource ('encoded video content'). It is distinguishable from siblings like get_info_height and get_info_duration by focusing on width alone, though it does not explicitly contrast with them.

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 implies usage by indicating it retrieves a specific piece of video info, but does not provide explicit when-to-use guidance or exclusions such as 'use this instead of X when'. The billing per call note is a contextual hint but not usage guidance.

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