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

With no annotations, the description carries the burden of disclosing behavior. It does disclose a key trait: it returns page_url and explicitly states there is no direct media URL. However, it does not mention what happens for invalid hashes, error responses, or any other side effects, leaving some behavioral uncertainty.

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, front-loaded sentence that conveys the core purpose and the most important caveat. Every word earns its place, with no redundant or filler content.

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 metadata lookup, the description covers the essential context: what it returns (metadata), how to identify the video (hash), and a critical limitation (no direct media URL). It does not enumerate all metadata fields, but since there is no output schema, a bit more detail could be offered; however, the description is still adequate for basic usage.

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 fully documents the hash parameter with a description ('Video hash (8+ hex chars)'), and the description merely repeats 'by hash' without adding new meaning. Since schema coverage is 100%, the baseline of 3 applies; the description adds no extra semantic value.

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 uses a specific verb ('Fetch') and identifies the exact resource ('metadata for one DesAira video') keyed by hash. This clearly distinguishes it from sibling tools like get_feed or get_trending, which operate on collections rather than individual videos.

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 when a hash is available (e.g., 'by hash'), but it does not explicitly state when to prefer this over alternatives or when not to use it. It provides no comparison to sibling tools or exclusion criteria, leaving the usage context implicit.

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