check_screenshot_cache

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

Despite no annotations, the description discloses a key behavioral trait: it does not count against quota. This is important for usage optimization. It does not mention return values or side effects, but the tool is simple and low-risk.

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, zero wasted words. The description is front-loaded with the primary purpose and immediately adds a key differentiator (quota). Perfect conciseness.

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 cache-check tool with no output schema and clear sibling context, the description is sufficient. It explains the core function and a critical behavioral note. Minor gap: does not describe the return format (e.g., boolean), but not essential for an agent to 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?

Input schema has 100% description coverage with basic descriptions for 'url' and 'format'. The description adds no additional insight beyond the schema, so it meets the baseline for schema-rich tools but does not enhance understanding.

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 verb 'check' and the resource 'screenshot cache'. It distinguishes from sibling 'take_screenshot' by noting it does not capture a new screenshot, and adds a unique benefit: not counting against quota. This is specific and helpful.

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 the tool is for verifying cache before capturing, but does not explicitly state when to use vs. 'take_screenshot' or 'get_usage'. However, the sibling context and the phrase 'without capturing a new one' provide clear contextual guidance.

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