query

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It does not state whether the operation is read-only, whether the screenshot is transmitted to an external service, what the response format is, or any privacy implications. The tool name and description imply a non-destructive query, but the lack of explicit behavioral context is a significant gap.

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, with the first sentence stating the purpose and the second providing a specific usage tip. Every sentence earns its place, with no redundant or irrelevant information. It is front-loaded with the core purpose and efficiently communicates the essential usage nuance.

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 (9 parameters, nested object, no output schema), the description is too minimal. It does not explain expected return values, how to choose mode, or when to prefer this over sibling tools. The schema covers parameter semantics, but the description lacks high-level context for an agent to decide on usage scenarios and anticipate behavior.

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 all parameters are individually documented. The description adds a cross-parameter rule ('Omit both...') which is already implied by each parameter's 'Omit to capture the foreground window' phrasing. Thus, the description adds little beyond the schema, meriting the baseline score of 3.

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 tool's function: capture a screenshot of a window and ask a question about its content. It uses a specific verb ('capture' and 'ask') and identifies the resource (window content). However, it does not explicitly differentiate from sibling tools like 'capture' or 'see', which may also involve screenshots, so it misses the highest mark.

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 a clear usage instruction: omit both window_title and process_name to capture the focused foreground window. This gives context for a common use case. However, it does not explain when to use this tool over alternatives like 'capture' or 'see', nor does it mention exclusions or prerequisites (e.g., screen mode allowlist), so it falls short of explicit when/when-not guidance.

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