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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, and the description adds genuinely new behavioral facts: the tool emits code rather than performing an upload, never reads the user's machine, and never transmits video bytes. The remaining gap is failure behavior (e.g., what happens if the sha256 check fails), which is minor for a code-emitting tool.

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?

The description is short, front-loaded with the purpose, and each line carries distinct information (identity, prerequisite, usage steps, and the code-not-upload clarification). The middle sentence is compressed to the point of being slightly telegraphic, but no line is 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?

With no output schema, the description correctly fills the most important gap by stating that the return value is source code rather than an upload result. Combined with the sequencing prerequisite and safety clarifications, an agent has enough to invoke and use it correctly.

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?

The tool takes zero parameters, so the baseline is 4 and there is nothing the description needs to disambiguate. The mention of "filename" and sha256 refers to the returned helper's usage rather than this tool's inputs, and is clearly framed as post-call steps.

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 and resource ("Get the official local Python upload helper") and immediately scopes it against the upload siblings by stating it "returns code, not an upload." An agent can distinguish it from get_upload, sign_upload_parts, and create_upload_session without inspecting any 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?

It supplies an explicit ordering prerequisite ("after get_upload_instructions") plus the key follow-up actions (save as filename in the task temp dir, verify sha256, run locally). It does not explicitly say when to prefer this helper over a direct server-side upload path, so the exclusion side is only partially covered.

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