MCP YAML API

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

Annotations indicate this is a mutable (readOnlyHint: false), non-destructive, non-idempotent operation with open-world semantics. The description adds no behavioral context beyond the basic 'update' action, such as permission requirements, side effects, or response format. It doesn't contradict annotations but adds minimal value.

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 with a single sentence, 'Update an existing user.', which is front-loaded and wastes no words. It's appropriately sized for its minimal content, though this conciseness comes at the cost of detail.

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 mutation tool with 3 parameters, no output schema, and annotations covering only basic hints, the description is incomplete. It lacks details on parameter usage, behavioral nuances, and output expectations, making it inadequate for effective tool selection and invocation.

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?

With 0% schema description coverage, the schema only defines parameter types without descriptions. The description provides no information about parameters, such as what 'id', 'name', and 'email' represent or their constraints, failing to compensate for the schema's lack of detail.

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 'Update an existing user' clearly states the verb ('Update') and resource ('user'), but it's vague about what aspects can be updated and doesn't distinguish it from sibling tools like 'replaceUser' or 'createUser'. It provides a basic purpose but lacks specificity.

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?

No guidance is provided on when to use this tool versus alternatives such as 'replaceUser' or 'createUser'. The description doesn't mention prerequisites, exclusions, or context for usage, leaving the agent to infer based on tool names alone.

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