Discover CERN ROOT files within a named resource using glob patterns and limits, then inspect a returned path—without modifying files.
List CERN ROOT files in a configured named resource. Use pattern and limit to bound discovery; inspect a returned path next. Does not modify files.
| Name | Required | Description | Default |
|---|---|---|---|
| limit | No | ||
| pattern | No | Optional glob pattern | |
| resource | Yes | Resource name |
Changes observed during successful MCP inspections.
v0.3.1Input schema / additionalPropertiesAdded value: +falseInput schema / properties / limitAdded value: +{
+ "default": 100,
+ "maximum": 1000,
+ "minimum": 1,
+ "type": "integer"
+}v0.1.7Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so 'Does not modify files' largely restates structured data. The one piece of added context is that the resource must be pre-configured and named, implying a setup prerequisite. It says nothing about result volume, truncation, or what happens when limit is hit, which the schema's maximum of 1000 hints at but does not explain.
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?
Three short clauses, front-loaded with the core action, and no filler. The final sentence 'Does not modify files' is mostly redundant with the read-only annotations and is the one element that does not earn its place.
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 small three-parameter read tool with no output schema, the description covers what it returns implicitly (paths to inspect), the knobs that bound results, and the safety profile. It could state the return shape (a list of paths) explicitly, but an agent has enough to call it 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?
Schema description coverage is 67%, and the schema itself only documents pattern as 'Optional glob pattern' and resource as 'Resource name'. The description adds purpose for both pattern and limit ('to bound discovery'), which is meaningful guidance the schema lacks. It does not explain the limit default or the 1000 cap, so it adds value but not fully.
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 gives a specific verb and resource ('List CERN ROOT files') scoped to 'a configured named resource', which clearly separates it from siblings like inspect_file, list_branches, or validate_file. It stops short of explicitly naming a sibling to disambiguate against, so it is clear but not maximally differentiated.
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?
It tells the agent how to bound the call ('Use pattern and limit') and routes the next step explicitly ('inspect a returned path next'), which is genuine workflow guidance pointing at inspect_file. It does not state when not to use this tool (e.g. for non-ROOT files or unconfigured resources), so it falls short of a full when/when-not treatment.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.