propzapi

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

With no annotations, the description carries the burden of disclosing behavior. It mentions the cost ('1 credit per image') and that cost is returned in _meta, plus that the image is returned. This adds meaningful context beyond a simple action statement, though it doesn't detail all side effects or failure modes.

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 long, immediately states the purpose, and then provides essential usage and cost information without any filler. Every sentence 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?

Given the tool's complexity (nested object, template requirement, cost), the description covers the key points: the need to list templates first, the cost, and the return value. It lacks detail about the output format beyond 'return the image,' but no output schema exists, so this is a minor gap. Overall, it is sufficiently complete for an agent to invoke 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?

Schema coverage is 67%, and the description adds the crucial instruction to use list_templates for template ids and variables, enhancing the template parameter's meaning. However, it doesn't elaborate on the format or modifications parameters beyond what the schema already provides, so it only partially compensates for the missing coverage.

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 action: render an image from a template and user data. It distinguishes itself from siblings by explicitly mentioning template-based generation and referencing list_templates, which is a separate tool for browsing 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 gives an explicit prerequisite: 'Use list_templates first to see template ids and their variables.' This provides a clear usage path and an alternative (list_templates) for selecting templates, which helps avoid misuse.

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 provided, the description carries the full burden. It adds useful context: the tool costs 1 credit, cost is in _meta, and only public pages are supported. It does not mention error handling, rendering behavior, or timeouts, but the key constraints are covered.

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 a single, front-loaded sentence that states the purpose, scope, and cost. No wasted words; every element 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 screenshot tool, the description conveys the core purpose and return type. However, with no output schema and minimal annotations, it lacks details on formatting options, error scenarios, and full behavioral expectations. It is adequate but not fully complete.

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 only 40% (url and full_page have descriptions). The tool description adds no parameter details, leaving width, format, and height semantics unexplained. Since coverage is low, the description should compensate but does not.

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 action: 'Screenshot any public web page and return the image.' It uses a specific verb and resource, and the scope ('any public web page') distinguishes it from sibling tools like generate_image (creates new 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?

The description implies when to use the tool: when a screenshot of a public web page is needed. However, it provides no explicit guidance on alternatives or exclusions (e.g., use generate_image for creating images). The context is clear but not detailed enough for a 4.

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