propzapi

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

No annotations, so the description carries the full burden. It discloses a cost side-effect ('1 credit per image; cost returned in _meta') and the prerequisite of listing templates. It clearly identifies the operation as template-based rendering, not generative AI. It doesn't specify output format or error behavior, but this is solid for a non-destructive render tool.

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 concise, front-loaded sentences. The first sentence states the purpose; the second gives prerequisite and cost. No wasted words or redundancy.

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 tool with a rich 5-param schema and no output schema, the description covers the core return behavior (image), prerequisite (list_templates), and cost. It doesn't explicitly state how the image is delivered (bytes/URL) or failure modes, but the schema's verify/receipt parameters hint at these. Overall adequate for an agent to select and invoke 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?

Schema coverage is high (80%) with descriptions for verify, receipt, and template. The description adds workflow context by stating template ids and variables come from list_templates, which clarifies both the template and modifications parameters. This goes beyond the schema and earns a 4.

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 'Render an on-brand image from a template and your data, and return the image' with a specific verb and resource. It distinguishes itself from siblings list_templates (listing template ids) and screenshot_url (capturing a URL) by emphasizing template-based rendering.

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?

Explicitly instructs to 'Use list_templates first to see template ids and their variables', establishing a clear prerequisite workflow. It also mentions credit cost and _meta return, giving practical usage context. No explicit alternatives/negations, but the guidance is sufficient for when to use.

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 burden. It discloses that listing is free and that the output includes template variables, which is useful. However, it does not explicitly state the read-only nature or lack of side effects, although 'List' implies it. Missing explicit cost/rate-limit details beyond 'Free'.

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?

A single, front-loaded sentence with no wasted words. It states the verb, resource, and key output detail ('variables') in under 15 words.

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 zero-parameter, no-output-schema listing tool, the description fully covers what it does, what output to expect (templates and their variables), and the cost ('Free'). No gaps remain.

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 baseline is 4. The description adds no parameter info (none needed) and instead focuses on output details ('variables each accepts'), which 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 uses a specific verb 'List' and clearly identifies the resource: 'image templates you can render.' It also notes the included detail ('variables each accepts'), distinguishing it from siblings like generate_image (which renders) and screenshot_url (which captures URLs).

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 phrase 'you can render' implies this is the tool to consult before generating images, and the contrast with generate_image/screenshot_url is clear. However, it does not explicitly state when not to use it or name alternatives, so it falls just short of a 5.

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 discloses the credit cost and the 'public web page' constraint. But it doesn't disclose error behavior, rate limits, or what happens for private/inaccessible pages, leaving significant behavioral gaps.

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 short sentences, front-loaded with the action, no redundancy. 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?

The description covers the core function, cost, and public-page constraint. However, it doesn't mention the customizable parameters (width, height, format, full_page, receipt) or the return format details, though the schema fills some gaps.

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 50%, and the description does not add semantics for width, height, or format beyond the schema's enum/defaults. It only reiterates the 'public web page' aspect already in the url schema description.

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 uses a specific verb ('Screenshot') and resource ('any public web page'), clearly distinguishing it from sibling tools like generate_image (creates images) and list_templates (lists templates).

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 clearly states the tool captures any public web page, giving clear context for when to use it. However, it doesn't explicitly mention alternatives or when not to use it, such as for pages requiring authentication or for generating new images.

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