search_transcript

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

Annotations already communicate readOnlyHint=false and idempotentHint=false, but the description adds critical context: the tool costs 1 credit per video and that the transcript is fetched server-side to perform the search. Disclosing that this is a paid call addresses a primacy-of-information concern (cost before running). Could go higher with rate limits or error behavior, but the credit disclosure is meaningful and not derivable from annotations.

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 focused sentences. The first states the action and output, the second discloses cost and mechanism, the third provides a routing rule. Every sentence earns its place with no redundancy or fluff.

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 100% schema documentation and meaningful annotations (readOnly=false, openWorld=true), the description is nearly complete. It covers the what, the cost, the routing, and hints at the output structure ('matching moments with timestamps and deep links'). Missing details like pagination or error handling are minor; the credit disclosure addresses the most operationally important non-obvious behavior. Returns are probably JSON, but the description's mention of 'cite' implies a usable structure.

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% and all parameters are documented in the JSON schema itself, so the description isn't required to repeat them. The description adds value by implying how 'query' relates to matching ('All terms must appear near each other') which is already in the schema, but the description's mention of 'phrase or topic' clarifies the semantic matching. The contextSegments parameter has a default and type in schema, so the 4 is justified because the schema carries the load and the description adds the credit-scope nuance.

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 ('Search') with a clear resource ('one YouTube video') and outcome ('return the matching moments with timestamps and deep links you can cite'). It distinguishes itself from the sibling get_transcript by stating 'Use this instead of get_transcript when the user asks what a video says about something.'

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?

Explicitly states when to use this tool ('when the user asks what a video says about something') and names the alternative ('use instead of get_transcript'). It also provides a usage caveat about credits, which helps an agent decide when the cost is justified, going beyond a mere alternative mention.

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