Shepherd MCP

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

No annotations are provided, so the description carries full burden. It mentions pagination behavior, which is useful. However, it doesn't disclose other important behavioral traits: whether this is a read-only operation, what authentication is required, rate limits, error conditions, or what the response format looks like (especially critical since there's no output schema). For a tool with 4 parameters and no annotations, this is insufficient.

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 extremely concise - just two sentences that each earn their place. The first sentence states the core functionality with pagination, and the second provides valuable context about what sessions represent. There's zero waste or redundancy, and it's appropriately front-loaded with the main 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?

Given the complexity (4 parameters, no annotations, no output schema, multiple similar sibling tools), the description is incomplete. It doesn't explain the return format, error handling, authentication requirements, or when to use versus search alternatives. For a list operation with pagination and timestamp filtering, more context about response structure and usage scenarios would be needed for an agent to use it effectively.

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 the schema already fully documents all 4 parameters with their types and descriptions. The description adds no additional parameter semantics beyond what's in the schema - it doesn't explain timestamp format, pagination behavior details, or relationships between parameters. With complete schema coverage, baseline 3 is appropriate.

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 ('List') and resource ('sessions'), and specifies that it includes pagination. It distinguishes from siblings by mentioning that sessions group related traces together, which provides context about the resource type. However, it doesn't explicitly differentiate from other list/search tools in the sibling set (like langfuse_search_sessions or list_sessions).

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 no guidance on when to use this tool versus alternatives. With multiple similar tools in the sibling set (langfuse_search_sessions, search_sessions, list_sessions), there's no indication of when this paginated list is preferred over search functionality or other listing tools. No prerequisites, exclusions, or alternative recommendations are mentioned.

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