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

Annotations already declare readOnlyHint=true, openWorldHint=false and destructiveHint=false, so safety is covered structurally. The description adds non-obvious behavioral detail beyond annotations: results are newest first and an active Revid plan is required. Pagination or rate-limit behavior is not mentioned, which keeps it from a 5.

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 short sentences: purpose and return shape first, downstream workflow second, access prerequisite last. Every sentence adds distinct value and the most important information is front-loaded.

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 zero-parameter list tool with an output schema and full annotations, the description covers everything an agent needs: what is listed, ordering, returned attributes, plan requirement, and how the result feeds create_episode. Nothing material is missing.

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?

This tool takes zero parameters, so there is no parameter semantics to add; the baseline for 0 params is 4. The mention of seriesId refers to create_episode's parameter rather than this tool's input, so it does not misrepresent 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 opens with a specific verb and resource ('List the account's Series Maker series') and immediately adds ordering ('newest first') plus the fields returned (style, ratio, video model, episode count). That distinguishes it from generic sibling list tools like list_projects or list_characters without the agent needing to inspect the 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 clear context for the tool's role in a workflow: pass a seriesId to create_episode to continue a series. It does not explicitly exclude alternatives or state when not to use this versus another list endpoint, so it falls short of a 5, but the implied use case is unambiguous.

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