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

Annotations only provide a title and destructiveHint=false, so the description carries the behavioral burden. It adds valuable context: base64 inflation (~33%), the ~6 MB request cap, the 'Parse error' failure mode, persistence of the asset, @-mentionability, and that no credits are consumed. There is no contradiction with annotations.

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 front-loaded with the core purpose and the most important constraint. Every sentence earns its place: size limit, failure mode, alternative workflow, persistence result, and credit cost. It is dense but not padded.

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 tool with no output schema and minimal annotations, the description covers invocation needs well: required inputs, size constraint, failure behavior, alternative route, and post-upload outcome. The only notable gap is the absence of any hint about what the successful response returns, but the tool's role is still unambiguous.

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 80%, so the schema already documents most parameters. The description adds practical meaning beyond the schema by clarifying content_base64 as raw file bytes and reinforcing the ~6 MB size limit with the base64 inflation explanation. It does not detail project_id or the optional name, but those are adequately covered by the schema.

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 states a specific action and resource: upload a small raw file into a project library via base64-encoded bytes. It also distinguishes itself from the larger-file workflow by naming the alternative tools to use instead. The result is clear: the file becomes a persistent, @-mentionable asset.

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 description gives explicit when-to-use guidance: use this tool for files under ~6 MB, and use video_editor_request_upload → PUT → video_editor_add_reference for anything bigger. It also notes the platform cap and the failure mode, so an agent can route correctly before invoking.

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