generate_marble

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

Annotations already declare readOnlyHint=true and idempotentHint=true, indicating safe, repeatable operations. The description adds valuable context about what the tool produces (ASCII diagrams for visualization) and the domain (RxJS stream emissions), which isn't captured in annotations. No contradiction with annotations exists.

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, efficient sentence that front-loads the core purpose without unnecessary words. Every element ('Generate ASCII marble diagrams', 'visualize RxJS stream emissions', 'over time') contributes directly to understanding the tool's function.

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 moderate complexity (4 parameters, no output schema), annotations cover safety (read-only, idempotent), and schema fully documents parameters, the description provides adequate context by specifying the visualization output and RxJS domain. However, it lacks details on output format or error handling, which could be useful despite no output schema.

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 parameters are fully documented in the schema. The description doesn't add any parameter-specific information beyond what's in the schema, such as explaining event structure or scale implications. With high schema coverage, baseline 3 is appropriate as the description doesn't compensate but schema handles 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 clearly states the specific verb ('Generate') and resource ('ASCII marble diagrams') with the purpose 'to visualize RxJS stream emissions over time'. It distinguishes from sibling tools like analyze_operators or execute_stream by focusing specifically on visualization rather than analysis, execution, or debugging.

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 context (visualizing RxJS streams) but doesn't explicitly state when to use this tool versus alternatives like analyze_operators or suggest_pattern. No explicit when-not-to-use guidance or prerequisite information is provided beyond the implied visualization purpose.

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