Vercel 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. 'Cancels' implies a mutation, but it doesn't specify effects like whether it stops processes, requires permissions, or has side effects. This is inadequate for a tool that likely alters system state without safety cues.

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, 'Cancels a deployment', which is front-loaded and wastes no words. It efficiently states the core action without unnecessary elaboration.

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 no annotations and no output schema, the description is incomplete. It doesn't cover behavioral traits, usage context, or return values, leaving gaps in understanding how to invoke it safely or interpret results, especially given sibling tools.

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 documents all three parameters. The description adds no meaning beyond the schema, such as explaining relationships between 'deploymentId', 'slug', and 'teamId'. Baseline 3 is appropriate as the schema does the heavy lifting.

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 states the tool's purpose ('Cancels a deployment') with a clear verb and resource, but it's vague about what 'cancel' entails compared to siblings like 'deleteDeployment'. It doesn't distinguish this tool from alternatives, leaving ambiguity about whether cancellation is reversible or different from deletion.

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. With siblings like 'deleteDeployment' and 'getDeployment', the description lacks context on prerequisites, timing, or exclusions, such as whether it applies only to active deployments or has specific conditions.

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