youtube_search

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the agent knows it's safe. The description adds valuable context beyond annotations: 'Free, no API key' (no auth/access issues), 'Filters combine' (explanatory logic), and 'Returns video ids' (output format). It does not contradict 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 sentences, each earning its place: first states purpose and filters, second gives a concrete example, third covers key non-obvious facts (free, no API key) and output destination. No fluff, well front-loaded.

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?

Despite 9 parameters and no output schema, the description is complete: it covers the core functionality, example usage, cost/auth requirements, and return value. The schema thoroughly documents all parameters, and sibling tools provide context for downstream 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?

Schema description coverage is 100%, so parameters are already well-documented. The description adds value by providing a concrete example of how filters combine ('a video about X with over 50,000 views, posted in the last month, from a channel with over 80,000 subscribers'), which illustrates parameter interaction beyond individual schema descriptions.

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 with a specific verb ('Search YouTube') and resource, then enumerates the filter dimensions (view count, recency, video length, subscriber count). It distinguishes itself from sibling transcript tools by noting it returns video IDs for use with youtube_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?

The description implies usage context: it's a search/filter tool for finding videos, and explicitly mentions passing results to youtube_transcript, providing a clear workflow. It does not explicitly say 'use this when X, use alternative when Y,' but the sibling tool names and the stated output make the distinction obvious.

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