get_transcript

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

With no annotations, the description carries full responsibility for disclosing behavior. It meaningfully describes the output structure (segments[], display_timestamp, end_seconds, match_count, language metadata, next_steps[]), which goes beyond the input schema and gives the agent a clear picture of what to expect. It stops short of documenting potential edge cases (e.g., no captions available, rate limits), but for a read-only fetch tool, the transparency is reasonably strong.

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 exactly two sentences: the first states the core purpose and capabilities, the second outlines the JSON return structure. Every sentence earns its place, the most critical information is front-loaded, and there is no redundancy or filler. It is ideal in size and structure.

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 tool with 8 parameters and no output schema, the description does a solid job of conveying the essential context: what the tool does, the modes of operation, the key returned fields, and the alternative for structured overviews. It is not exhaustive—for instance, it doesn't demonstrate how parameters combine—but it is sufficient for an agent to correctly select and invoke the tool for typical use cases.

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 description coverage is 100%, so the baseline is 3. The description adds light narrative context by summarizing modes ('full text, keyword search, time range, or paginated segments'), but each parameter is already thoroughly explained in the schema. The description does not add significant meaning beyond what the schema already provides, so no higher score is warranted.

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's function: 'Fetch YouTube captions for one video' with specific modes (full text, keyword search, time range, paginated segments). It distinguishes from the sibling summarize_video by explicitly directing structured overviews there, making the tool's specific purpose unambiguous.

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 provides clear usage context by enumerating the types of transcript tasks it supports and explicitly notes that 'Structured overview of a video uses summarize_video,' which serves as a when-not/alternative directive. This is sufficient guidance for an agent to decide between get_transcript and summarize_video, and implicitly differentiates from youtube_query by focusing on caption retrieval.

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