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

Annotations declare the safety profile (readOnlyHint=false, destructiveHint=false), and the description adds genuinely useful context beyond them: 'Saves nothing' clarifies there is no persistence, and 'counts against the monthly AI allowance' discloses a quota cost. Return format is not described, but no output schema exists to cover it either.

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 tight sentences, front-loaded with the purpose before the behavioral caveats. Every sentence carries distinct information with 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?

For a one-parameter generation tool the description covers purpose, cost, persistence behavior, and workflow placement. The only omission is what the returned script looks like, which is minor given no output schema exists.

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?

With a single parameter at 100% schema description coverage, the schema already defines post_text and its length bound (1–4000 characters). The description adds no extra parameter meaning, so the baseline 3 for schema-covered parameters 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 (write), a precisely scoped resource (short talking-presenter video script), and the input it derives from (a post's text). An agent can distinguish this from generate_video, which produces the finished video rather than the script.

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 positions the tool in a workflow: 'Show the script to the user before generate_video,' which tells the agent this is a preceding step, not a terminal action. It does not name an explicit when-not-to-use condition, keeping it short of a 5.

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