moodle-mcp

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

With no annotations provided, the description carries full burden and does well. It discloses behavioral traits: success returns '{ data }' and failures return structured 'meta.code' + 'isError: true'. It also implies this is a low-level, potentially risky operation ('escape hatch'), though it doesn't detail authentication needs, rate limits, or specific error conditions.

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 appropriately sized and front-loaded. The first sentence states the core purpose, the second explains return behavior, and the third provides usage guidance. Every sentence adds value with zero waste, making it efficient 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 (low-level API access with arbitrary parameters), no annotations, no output schema, and 0% schema coverage, the description is reasonably complete. It covers purpose, behavior, and usage guidelines. However, it lacks details on authentication, error specifics, or parameter examples that would be helpful for such a flexible tool.

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 0%, so the description must compensate. It adds meaning by explaining that 'function_name' corresponds to 'any Moodle Web Services function' and 'params' are 'arbitrary parameters'. However, it doesn't provide examples, format details, or constraints beyond what the schema's pattern hint suggests. This partial compensation earns a baseline score.

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 tool's purpose: 'call any Moodle Web Services function with arbitrary parameters.' It specifies the verb ('call'), resource ('Moodle Web Services function'), and scope ('any' with 'arbitrary parameters'). However, it doesn't explicitly differentiate from sibling tools, which appear to be more specific Moodle operations.

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 explicit usage guidance: 'Prefer high-level facades when they cover your use case.' This directly tells the agent when to use this tool (as an 'escape hatch' when other tools don't cover the need) versus when to use alternatives (the 'high-level facades'). The 'escape hatch' framing further clarifies this is a fallback option.

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