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

Annotations declare readOnlyHint=false, openWorldHint=true, idempotentHint=false, destructiveHint=false. The description adds meaningful behavioral context beyond these: it states that the tool is free, that it returns projectId and characterIds, that nothing is generated yet, and that certain parameters (imageModel, aspectRatio, stylePreset) are 'Locked once created.' It also discloses cost/charging behavior for downstream steps. The only minor gap is that it doesn't explicitly describe failure modes or what happens if required fields are invalid, but the description goes well beyond the annotations.

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 earns its length: it front-loads the core purpose in the first sentence, then provides a numbered pipeline that is directly actionable. The pipeline list is dense but well-structured. It could be slightly tighter (e.g., the cost details for downstream tools are useful but somewhat tangential to this tool's own invocation), but every section serves a purpose for an agent navigating the workflow.

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 complex 16-parameter tool with no output schema, the description is remarkably complete. It explains the return value (projectId, characterIds), the workflow position, the sequencing constraint with character_reference, the meaning of key parameters, and the locked-parameter behavior. An agent has everything it needs to call this tool correctly and to know what happens next. The absence of an output schema is compensated by the explicit statement of what is returned.

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 all 16 parameters. The description adds value by explaining the semantic role of key parameters: 'Characters: give each a concrete visualDescription (age, hair, face, clothes, one signature item). The script writer and every panel read it.' It also clarifies that 'custom' artStyle means describing the look in toneNotes, and that the cover is drawn around the protagonist. This is meaningful semantic guidance beyond the schema's field descriptions.

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 clear verb and resource: 'Creates a comic book project (the AetherWave Graphic Novel Engine) and returns its projectId and each character's characterId.' It also explicitly states what it does NOT do ('Nothing is generated yet'), which distinguishes it from later pipeline tools like aetherwave_comic_draw and aetherwave_comic_write_script. This is a specific, non-tautological statement that an agent can act on.

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 provides an explicit numbered pipeline of all sibling tools, stating the order of operations and when to use each one. It also gives a critical usage rule: 'Do this BEFORE the script: approving rewrites the character's description from the picture, and every panel uses the approved image to keep the face consistent.' This is exactly the kind of when-to-use and sequencing guidance an agent needs.

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