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

With no annotation hints (all false), the description carries the full burden. It discloses that it's project-scoped, acts only on explicit project_id, returns the project identity, writes a sparse motion pass, derives stress from audio and times from word timestamps, uses face targets when detected, and prefers zero or one hard punch. It also warns about not calling without justification. This is comprehensive behavioral disclosure with no contradictions.

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 long but each sentence delivers unique information—scope, usage conditions, parameter guidance, and fallback. It's front-loaded with the most critical scope warning. Slightly verbose but not redundant; earns its length. Could be tightened slightly but is efficient for the complexity.

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?

Given the tool's complexity (specialized effect, 3 params, no output schema, no annotations), the description covers all necessary aspects: what it does, when to use, how to parameterize, what it returns, and alternatives. It even addresses edge cases like face detection and why to avoid calling. No missing information that an agent needs.

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 only 33% (only project_id has a description). The description compensates by explaining count as density ('Omit count to keep density sparse') and strength as magnitude ('omit strength to keep magnitude small'). It also adds context like 'Prefer zero or one hard punch over a sprinkle' which clarifies how to set parameters. This gives meaning beyond 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 clearly states the tool's function: adding a sparse, timeline-distributed motion pass on vocally stressed words. It distinguishes itself from siblings by explicitly saying it's not a default pass, not 'make it high-retention', and not a talking-head finish, and even names add_zoom as an alternative. The verb+resource is specific and unambiguous.

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 provides explicit when-to-use conditions ('ONLY when the user explicitly asked for punch-ins on stressed / important spoken words') and when-not-to-use scenarios ('Not a default pass... not a talking-head finish'). It also gives a concrete fallback: 'hold the frame or use one add_zoom(mode='ease')' if the agent can't justify a bump. This fully guides tool selection.

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