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

With no annotations, the description carries the full burden of behavioral disclosure. It clearly conveys sequential/partial reading through cursors, the inability to jump to a position, and the critical warning that returned text is third-party content whose instructions must not be followed. This gives an agent robust expectations beyond the schema.

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?

Every sentence earns its place: a clear one-line definition, parameter usage, a rationale distinguishing it from search, and a security warning. The core purpose is front-loaded, and there is 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?

The description fully covers how to initiate, how to continue, when this tool is necessary, and a content-safety caveat. Since an output schema exists, not explaining return values is acceptable. Nothing an agent needs to call this correctly is missing.

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%, with both uid and cursor already described in the input schema. The description reiterates that uid comes from a crossload_search hit and that nextCursor continues from the previous response, but adds no meaningful semantics beyond what the schema already provides. Baseline 3 is appropriate.

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 ('Read') and resource ('transcript of one content item'), and specifies the sequential, portion-based mode. It distinguishes itself from crossload_search by stating that search returns items but never a position within one, making the tool's unique purpose clear.

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?

It explicitly explains how to use the tool: pass the uid from a crossload_search hit and pass nextCursor from the previous response to continue. It also gives a clear when-to-use rule — this is the only way to locate a particular sentence inside a long item — while contrasting with what search cannot do.

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