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

Annotations only say readOnlyHint=false and destructiveHint=false, so the description carries most of the weight — and it delivers: cost ('Free'), side-effect scope ('nothing is rendered'), an idempotency warning, caption behavior, and the fact that the quote arrives in the response. It stops short of stating auth/permission requirements or rate limits.

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-loads the key fact ('Free') and the core purpose in one sentence, then uses compact Args/Returns blocks. The caption note is a single aside that carries real behavioral meaning, so nothing here is padding.

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?

With no output schema, the Returns block usefully spells out {ok, project:{id, status, scenes, quote}} and flags the price field the agent needs next. Given a nested music_plan parameter, the missing explanation of plan contents is the only real gap.

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 67% and already documents song_id's source and music_plan's origin; the description largely restates them ('a read song', 'the plan to make'). The nested music_plan object is still opaque — its internal structure is neither described here nor in the schema — so this earns baseline rather than more.

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 ('Makes a Studio project from the plan') and immediately scopes it with 'nothing is rendered', which separates it from studio_render and from the director/estimate siblings. An agent can tell what this produces without opening 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?

Gives explicit workflow ordering: create the project, then price it, then call studio_render(project_id, confirm_cents), plus the guard 'never call it twice for one plan'. It does not explicitly exclude studio_create_project or studio_create_from_audio, so sibling selection guidance is incomplete rather than absent.

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