upload_media

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

Annotations indicate mutable (readOnlyHint=false) and accepts unknown values (openWorldHint=true). The description adds only the '3-step flow' note, which is procedural rather than behavioral. It does not disclose side effects like consumption of rate limits, creation of a media ID, or potential failure reasons. Since annotations are minimal, the description should provide more transparency.

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 a single concise sentence that immediately conveys the core purpose and key process. It is well front-loaded with the verb and resource. However, it could be slightly expanded to include the output or usage note without losing conciseness.

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?

The tool has no output schema and the description does not mention what the tool returns (e.g., a media ID or success status). Given the complexity of a 3-step process, the description is incomplete without explaining how the single call handles the flow. It also omits common constraints like file size limits or supported formats.

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% (all three properties are described). The description adds no additional meaning beyond what the schema provides, but that is acceptable when coverage is high. The mutual exclusivity of media_url and media_data is already in the schema descriptions, so no extra value is needed. Score is baseline 3.

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 clearly states the verb and resource: 'Uploads media to Twitter'. It also mentions the specific '3-step INIT/APPEND/FINALIZE flow', which distinguishes it from other tools. However, it does not explain what the tool returns or how the flow is handled within a single call, leaving some ambiguity about its exact function.

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 provides no guidance on when to use this tool versus alternatives. While sibling tools are all different, there is no mention of prerequisites (e.g., authentication, file size limits) or when not to use it. The context implies it is for media upload, but explicit usage conditions are missing.

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