take_screencast

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

Annotations provide readOnlyHint=true and destructiveHint=false, indicating safe operation. The description adds valuable behavioral context beyond annotations: adaptive frame rates (100ms, 200ms, 500ms intervals), output formats (PNG as individual frames, WebP as animated with 4-second pause), and format-specific details. It does not contradict annotations, as 'capture' aligns with read-only behavior.

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 appropriately sized and front-loaded, starting with the core purpose. It efficiently covers key behavioral traits in two sentences without redundancy. However, it could be slightly more structured by separating format details into distinct points for clarity.

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, no output schema) and rich annotations, the description is mostly complete. It explains adaptive frame rates and format behaviors, which are critical for usage. However, it does not cover all contextual aspects like error handling or performance implications, leaving minor 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 100%, so the schema fully documents all 9 parameters. The description adds minimal parameter semantics, mentioning PNG and WebP formats and adaptive frame rates, which relate to 'format' and 'duration' parameters but do not provide significant additional meaning beyond the schema. Baseline 3 is appropriate given high schema 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 tool's purpose: 'Capture a series of screenshots of a web page over time, producing a screencast.' It specifies the verb ('capture'), resource ('web page'), and output ('screencast'), distinguishing it from sibling tools like 'take_screenshot' (single screenshot) and 'capture_console' (different resource).

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 usage through details like adaptive frame rates and format options, suggesting when to use it for time-based captures. However, it lacks explicit guidance on when to choose this tool over alternatives like 'take_screenshot' or 'capture_console', and does not mention prerequisites or exclusions.

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