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

Annotations already declare readOnlyHint and idempotentHint, so the safety profile is known. The description adds valuable context: auth requirement (creator:submit scope), the specific data returned (states, view counts, amounts in cents), and that it only lists the caller's own videos. 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 two sentences, front-loaded with the intended audience ('For CREATOR API keys'), and every sentence contributes essential information (what is listed, states, auth requirement). No wasted words.

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 simple listing tool with only two optional parameters and an output schema, the description is complete. It covers the purpose, data returned, auth, and filtering. Return values are handled by the output schema, so no need to elaborate further.

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 both parameters ('before' and 'campaign_id') have descriptive comments in the schema. The description only mentions 'Optionally filter by campaign_id' without adding new meaning beyond what the schema already provides, so the baseline score of 3 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?

The description clearly states the tool lists 'your submitted videos' with specific state values (submitted/published/validated/revision/paid), view counts, and validated amounts in cents. It uses the specific verb 'lists' and identifies the resource (deliverables), distinguishing it from the sibling 'list_my_campaigns' which lists campaigns.

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 clear context by stating 'For CREATOR API keys' and mentions the required scope (creator:submit), which indicates who should use it. However, it does not explicitly exclude alternatives or state when not to use it, so it falls 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.