Tapercraft — VHS Label Maker

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

With no annotations, the description carries the full burden and does so well: it discloses the return shape (a URL), the free-vs-membership gating of export, the 'unsupported' field semantics and how to report them, and the hard limitation that user image uploads cannot happen through this tool. These are exactly the non-obvious behaviors an agent would otherwise get wrong.

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?

Four sentences, purpose front-loaded, and each sentence adds an actionable constraint (free vs paid, unsupported fields, image upload workaround). Slightly dense but no filler; the third and fourth sentences are both operative caveats, not 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?

For a 5-parameter nested tool with no output schema and no annotations, the description covers the deliverable (URL), the completion workflow, the failure mode (unsupported fields), and the one capability the tool lacks (file uploads). Nothing an agent needs to call it correctly is missing.

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 60%, and the description meaningfully compensates: text overrides apply only to video formats (unsupported on audio), finish values and their jcard special case, useLogo's default when text.title is set, and that audio builds a full design from the album alone. It adds real semantics beyond the schema, though a few parameters (layout.hide details beyond the enum, background.color) are left to 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?

States a specific verb and resource ('Build a label design') and the concrete deliverable ('return a URL the user opens to finish it'). This is clearly distinguishable from list_formats and search_content, which enumerate formats and resolve content ids respectively.

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 clear operating context: designing/previewing are free, exporting a print-ready file requires a membership, and the URL is a starting point completed in the browser. It does not, however, route the agent to sibling tools (e.g., search_content for an id, list_formats for a format) — that routing lives only in the schema, so exclusions/alternatives are not fully covered in the description itself.

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

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

With no annotations, the description carries the full behavioral burden. It signals a read-only operation by saying 'List' and specifies the output content: 'printed dimensions.' For a zero-parameter listing tool, this adequately discloses what the tool does without needing to mention side effects.

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?

Two sentences with no wasted words. The core purpose is front-loaded, and the usage guidance is appended in a natural second sentence. Every part earns its place.

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 simple, zero-parameter list tool with no annotations or output schema, the description is complete: it states what is listed, what details are included, and when to invoke it. An agent has everything needed to call it correctly.

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 tool has zero parameters, so the description does not need to explain parameter meaning. The schema already reflects this with an empty properties object, and the description adds context about what the list contains.

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 states a specific verb and resource: 'List the packaging formats that can be composed, with their printed dimensions.' It clearly distinguishes itself from siblings like compose_design and search_content by focusing on format enumeration rather than design or content retrieval.

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 explicitly advises when to use this tool: 'Call this first if you are unsure which format the user wants.' This is clear contextual guidance, though it does not mention when not to use it or name alternative tools explicitly.

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

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It conveys that this is a read-only lookup returning candidate matches with years, which is useful. However, it does not explicitly state the absence of side effects, authentication needs, or rate limits, and it gives no detail on the structure of the returned candidates. This is adequate but not comprehensive.

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 two sentences with no filler. The first sentence front-loads the core functionality, and the second sentence provides actionable usage guidance. Every word earns its place.

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 simple two-parameter lookup tool with no output schema, the description covers the core purpose, the invocation context, and the general return shape (candidate matches with years). It could be more explicit about what happens when no matches are found or about the exact output format, but these are minor gaps in an otherwise self-sufficient description.

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 parameters are already fully documented in the input schema. The description reinforces that 'query' is a title search and that 'type' selects among movie/TV/album, but it adds little beyond the schema's own descriptions. Baseline 3 is appropriate.

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 states a specific action ('Look up') on a well-defined resource ('a movie, TV show, or music album by title') and clarifies the output ('return candidate matches with years'). This clearly distinguishes it from sibling tools compose_design and list_formats, which have entirely different purposes.

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 explicitly says when to use this tool: 'when the user's title is ambiguous and you want to confirm which one they mean before composing.' It provides clear context for invocation, although it doesn't explicitly name excluded alternatives or when-not-to-use conditions.

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