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

Annotations already cover readOnly, idempotent, and non-destructive behavior, so the bar is lower. The description adds real behavioral detail beyond that: the precise element-boundary rule (up to but not including the next SCENE_HEADING or structure element), the episodeIndex=0 convention, and the includeShots default. Auth/pagination context is not discussed, keeping it at 4.

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?

Purpose is front-loaded in the first sentence, and the dense return-shape explanation is justified by the absence of an output schema. It is long but every sentence carries information; only the element-ordering detail could be trimmed slightly.

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?

With no output schema, the description fully carries the burden of describing return values — element fields, entity links, character content/extension handling, and shot inclusion. Nothing an agent needs to call or interpret this read tool 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 description coverage is 100%, so all three parameters are already documented, including the sceneId source in the schema itself. The description adds only marginal meaning (reinforcing the outline/search source and the includeShots default), so the 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?

States a specific verb and resource ('Read one scene of the screenplay') and immediately enumerates what is returned, which cleanly separates it from list_shots, search_script, and get_project_outline. An agent can tell what this tool is for without opening the schema.

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 final sentence routes the agent to where sceneId comes from (get_project_outline or search_script), giving clear sourcing context and implicitly naming alternatives. It stops short of an explicit when-not statement or a comparison against siblings like list_shots, so it does not reach 5.

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