Mapbox MCP Server

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It mentions what the tool does but doesn't describe important behavioral traits: whether it requires authentication, rate limits, what happens when place names are ambiguous, error handling, or the format of returned matrices. For a complex tool with 8 parameters, this is a significant gap.

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 a single, efficient sentence that clearly states the tool's core functionality. It's appropriately sized and front-loaded with the essential information. There's no wasted verbiage or 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 complex matrix calculation tool with 8 parameters, no annotations, and no output schema, the description is insufficient. It doesn't explain what the output looks like (matrix format), doesn't mention authentication requirements, doesn't discuss rate limits or costs, and doesn't provide context about when this tool is appropriate versus alternatives. The description should do more given the tool's complexity.

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 8 parameters thoroughly. The description adds minimal value beyond the schema - it mentions 'using their names' which hints at the 'places' parameter, but doesn't provide additional context about parameter interactions or usage patterns. Baseline 3 is appropriate when 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 clearly states the tool's purpose: 'Calculate travel time and distance matrices between places using their names.' It specifies the verb ('calculate'), resource ('travel time and distance matrices'), and method ('using their names'). However, it doesn't explicitly differentiate from sibling tools like 'mapbox_matrix' (which likely uses coordinates rather than place names).

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. It doesn't mention sibling tools like 'mapbox_matrix' (which might use coordinates instead of place names) or 'mapbox_directions_by_places' (which might provide route details rather than matrices). There's no context about appropriate use cases or exclusions.

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