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

With empty annotations, the description carries the full behavioral burden. It discloses permission scope ('authenticated user is allowed to view'), single-item scope, and frames the call as polling, which implies safe repeated reads. It doesn't explicitly state 'no side effects', but 'fetch' and 'poll' are strong non-mutating signals.

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?

Two sentences, zero filler. The first sentence front-loads the core operation and scope; the second supplies the intended use case. Every clause earns its place and the whole text is easy to scan.

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 get tool with no output schema, the description is nearly complete: it states what is fetched, under what authorization, on which platforms, and for what purpose. It stops short of describing the return fields, but the phrase 'publishing outcome' already signals the relevant content. A brief return-format note would push this to 5.

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 single parameter 100% with its own description ('ID of the submission to fetch, on any platform'). The tool description adds minimal new meaning beyond that, mainly reinforcing the cross-platform aspect. Baseline 3 is appropriate because the schema does the parameter documentation work.

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 opens with a specific verb ('Fetch'), a concrete resource ('a single video submission'), and clear scope ('the authenticated user is allowed to view'). It also disambiguates from list and mutation siblings by emphasizing single-fetch semantics and naming the supported platforms. This is immediately actionable for an agent.

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 gives a clear use context: 'Use it to poll a submission for its publishing outcome.' This tells the agent when to invoke it. It does not explicitly name alternative tools or exclusions, but the distinction from list/cancel/delete submission tools is strongly implied.

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