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

Annotations already declare readOnlyHint=false, idempotentHint=false, destructiveHint=false, openWorldHint=false; the description adds that a *new* project is created (consistent with non-idempotent) and that it returns a link, plus the cost signal "Free." That cost detail is genuinely useful next to buy_credits/quote_job siblings and is not captured in annotations, though no permission or rate-limit context is given.

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?

Two compact sentences, with the core action and return value front-loaded in the first clause. The trailing editor-capabilities sentence (trims, captions, music, upscales, exports) is mildly ornamental but does orient the agent to the tool's downstream purpose.

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 two-param, low-destructive creation tool with no output schema, the description covers the action, resulting artifact (a new project plus link), accepted ID sources, and cost. Missing elements are minor: no statement about what happens on repeat calls or whether project limits/quota apply.

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 description coverage is 100%, and the clip_id description in the schema already spells out all three accepted ID sources in more detail than the prose. The description adds no extra meaning for the optional 'name' param, so baseline 3 applies.

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?

States a specific verb and resource: "Put a clip in a new PrismPoster editor project and get its link." It also clarifies the two clip provenances (account-made clip vs. the person's own clip imported via import_media), which separates it from pure-creation siblings like create_video, though it never names a conflicting sibling to avoid.

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?

Usage is implied rather than stated: the description explains where clip_id can come from (get_job, list_library, import_media), which is really input routing, and sketches what the editor is used for afterwards. There is no explicit when-to-use/when-not-to-use or alternative-tool guidance against the 27 sibling tools.

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