mark_highlight

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

No annotations are provided (neither readOnlyHint nor destructiveHint), so the description carries the full burden of behavioral disclosure. It doesn't state whether this is a lightweight metadata operation, whether it affects the broadcast output, whether it persists, or what side effects occur. For a tool with zero annotation coverage, this is a notable 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?

One sentence, zero waste. It's appropriately brief, though it could add useful information without becoming bloated. The structure is clean and front-loaded with the core purpose.

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?

This tool sits in a complex stream-management ecosystem with 16 siblings. Given zero annotations, zero output schema, and an undocumented parameter, the description is insufficient. An agent would not know what a 'highlight point' is, what the description parameter does, what the return value is, or how this interacts with the show lifecycle tools.

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 a single optional 'description' parameter at 0% schema coverage. The description doesn't explain what the description parameter is for - whether it labels the highlight, is stored, or is sent somewhere. With only one parameter, the description could easily explain its purpose, but it doesn't.

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 'Mark a highlight point in the stream' has a clear verb ('mark') and resource ('highlight point in the stream'), explaining what it does at a basic level. However, it doesn't distinguish itself from siblings like take_stream_snapshot or trigger_effect, which could overlap in purpose for an agent.

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?

No guidance is provided on when to use this tool versus alternatives like take_stream_snapshot or trigger_effect. The description gives no context about what a 'highlight point' means in the stream workflow or when marking one is appropriate.

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