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

With no annotations provided, the description carries the full behavioral burden and does so thoroughly. It discloses async job behavior ({id, status}, poll getApiJob), return value (audio URL only, no video), side effect (audio attached as audio_url in listGenerations), idempotency semantics, the 7-day validity window, and credit cost of 3 credits per call. This is exemplary behavioral disclosure.

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 dense but every sentence carries operational information: purpose, provenance constraint, applicability, result shape, attachment behavior, idempotency, and cost. It is front-loaded with the core purpose and the most important constraint. It is longer than typical descriptions, but the length is justified by the tool's complexity and lack of annotations.

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 there is no output schema, the description fully covers what an agent needs to know: how to construct the call, what the job result will be, how to poll, what side effects occur, and what it costs. The only deferred item is the detailed job/credit contract, which is explicitly referenced in the server instructions rather than omitted.

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?

The input schema already documents all three nested properties at 100% coverage, so the baseline is 3. The description adds meaningful value beyond the schema by linking spritesheet_video_url to outputs of specific sibling tools, emphasizing the 7-day freshness requirement, and clarifying that request_id must not be reused for other generations. This extra context justifies a score above baseline.

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: 'Generate a sound effect for a previously generated spritesheet animation.' It also distinguishes this from generic audio generation by requiring the spritesheet_video_url to come from specific sibling tools and by stating hydra spritesheets already have audio_url. This clearly separates it from siblings like createSoundEffect and createAmbiance.

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?

The description gives explicit when-to-use guidance: only for forge/forge-pixel output or to replace hydra's sound, and only for spritesheets generated within the last 7 days. It also explicitly excludes arbitrary external videos. This is strong routing information that prevents misuse.

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