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

Goes well beyond the readOnlyHint and openWorldHint annotations by disclosing the credit cost model (1+1=2, with long videos costing ~1 more per 45 minutes), the language behavior, and the transcript dependency. This is exactly the kind of operational context annotations cannot carry.

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?

Three tight sentences: purpose, language semantics, then cost. Front-loaded with the primary value proposition, no filler.

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?

Comprehensive for a 3-param read tool: it covers outputs, language handling, and cost. No output schema exists, but the description enumerates the deliverables. Minor gap: doesn't address failure modes (private/no-caption videos) despite the 'public' qualifier implying them.

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?

Schema coverage is 100%, so the baseline is 3, but the description adds meaning: it clarifies that translate_to changes which transcript is summarized (not just output language) and that output language follows the transcript. This exceeds what the schema field descriptions convey.

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?

States a specific verb (summarize) and resource (YouTube video) and enumerates the outputs (summary, key points, timestamped study notes). This clearly distinguishes it from the sibling get_transcript.

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?

Implies usage context: it operates on public YouTube videos and generates summaries from transcripts. The relationship to get_transcript is implied (this summarizes, that just fetches), but there are no explicit when-to-use/when-not statements or named alternatives.

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