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

Goes well beyond annotations: discloses that export is charged in credits, that the quote is bound to a timeline revision and expires after 15 minutes, that a stale quote must be regenerated, and that the project remains editable at editorUrl. This is exactly the contextual/behavioral detail annotations don't carry.

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?

Front-loaded with the core action and cost, then the numbered two-step flow, then return/polling behavior. Dense but every sentence earns its place with no filler.

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?

An output schema exists so return values needn't be detailed, yet the description still notes renderId and the polling sibling. Cost, confirmation requirement, expiry, and revision binding are all covered for a non-idempotent, chargeable operation.

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%, so the schema already documents projectId, quoteToken, acceptWarnings, and expectedRevision in detail. The description reinforces the flow (quoteToken only after user agreement, new quote if timeline changes) but adds little syntax or semantics beyond what the schema already provides; 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 ('Render the project to MP4') and distinguishes itself from siblings like video_project_edit and video_project_review. The two-step export nature is made immediately clear.

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?

Explicitly prescribes the when/how: step 1 without quoteToken to get a quote, show the price and wait for an explicit yes, then step 2 with the quoteToken. It also states when to re-quote (timeline changed) and routes polling to video_project_export_status.

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