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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered; the description goes further by disclosing that the result differs by deployment — the film's account address online versus a local file path when the connector is installed — and that the output is meant to be surfaced to the user rather than acted on. It does not describe failure behavior for an unknown or malformed name, which is the main remaining gap.

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 and little is truly redundant, but the prose is dense, fragmentary, and heavily colon-chained, so parsing costs real effort for what is four short facts. A cleaner statement of 'returns the film's URL or local file path, or the film list when name is omitted' would have been shorter and clearer.

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 one-optional-parameter read-only tool with no output schema, the description supplies the essentials: both output modes, the omit-parameter behavior, the relationship to list_films, and the instruction to hand the result to the user. Nothing an agent needs in order to call it 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% and the schema already documents the single prj_… id parameter, so baseline would be 3. The description earns above baseline by explaining the meaning of omitting the optional parameter entirely — the editor's « Mes films » list, including browser-local films the account does not show — which the schema's 'not required' flag alone does not convey.

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 opening clause states a specific action on a specific resource — opening a film in the Cutscene editor so the user can add pictures, preview it, and export — and the 'Online it is the film's address / with the connector, the film's file' sentence states exactly what the tool yields. It is distinguishable from get_film and list_films, though the circular phrasing ('Where the user opens a film ... to do by hand what is done there') forces the agent to re-read to extract the verb.

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 states when to reach for this (the user wants to work on the film by hand in the editor), covers the no-argument fallback ('Without a name, the editor's « Mes films »'), and explicitly contrasts that fallback with list_films ('where the user finds a film list list_films does not give'). No explicit exclusions are given, and the closing instruction 'Give it to the user with what is left for them to do' is a handoff rule rather than a use case.

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