cdl.start

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

With no annotations, the description carries the full burden. It reveals an important non-obvious behavior: CDL collection is continuous and cannot be toggled, so this tool merely marks the intended coverage window rather than starting/stopping collection. This is valuable context beyond the schema, though it doesn't detail effects on existing data or how the session is stored.

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 sentence that packs useful behavioral information without extra fluff. It is concise and front-loaded with the key constraint about continuous collection.

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?

The tool is relatively simple (one string parameter, no output schema), but the description leaves a major gap: it does not explain the `session` parameter or provide any usage scenario (e.g., 'call before running code to record CDL data'). Key context about the session identifier and workflow is missing, making the description incomplete despite the low complexity.

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 schema has one required parameter 'session' with 0% description coverage. The description mentions 'session's intended coverage window' but never explains what the `session` parameter should contain, what format it expects, or how it's used. The description fails to compensate for the missing parameter documentation.

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 explains that CDL collection is continuous and then says 'this marks the session's intended coverage window.' This gives a general sense that the tool marks the start of a coverage window, but it lacks a clear active verb like 'start' or 'begin.' It does distinguish from siblings by referencing the continuous nature and the window concept, but not strongly.

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 you use this to mark when you want coverage to count, since collection is always on. However, it doesn't explicitly say when to use it, what precedes it (e.g., loading a ROM), or when to use cdl.stop instead. The guidance is contextual but not explicit.

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