servicenow-mcp

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It mentions a prerequisite ('requires SCRIPTING_ENABLED=true'), which adds useful context about potential failure conditions. However, it lacks details on other behavioral traits such as permissions needed, whether the registration is permanent or reversible, error handling, or what happens on success (e.g., confirmation message). For a mutation tool with zero annotation coverage, this is a significant 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?

The description is a single, efficient sentence that front-loads the core action ('Register a new custom event') and includes a crucial prerequisite without unnecessary elaboration. Every word earns its place, making it highly concise and well-structured.

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 (a mutation operation with 3 parameters), lack of annotations, and no output schema, the description is minimally adequate. It covers the basic purpose and a key prerequisite but misses details on behavioral aspects, return values, and error handling. For a tool that modifies system state, this leaves gaps in contextual understanding.

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%, meaning all parameters are documented in the input schema. The description doesn't add any additional meaning or context about the parameters beyond what the schema provides (e.g., it doesn't explain relationships between 'name', 'description', and 'table'). With high schema coverage, the baseline score of 3 is appropriate as the description doesn't compensate but also doesn't detract.

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 ('Register') and resource ('new custom event in the event registry'), making the purpose specific and understandable. However, it doesn't distinguish this tool from potential siblings like 'fire_event' or 'get_event_registry_entry', which would require explicit differentiation to earn a 5.

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 provides some usage context by mentioning the prerequisite 'requires SCRIPTING_ENABLED=true', which implies when this tool might fail. However, it doesn't offer explicit guidance on when to use this tool versus alternatives (e.g., 'fire_event' for triggering events or 'get_event_registry_entry' for retrieval), leaving usage somewhat implied rather than clearly defined.

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