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 but only states the basic function without addressing critical aspects. It doesn't mention whether this is a read-only operation, potential rate limits, authentication requirements, error handling, or what the output looks like (e.g., matrix format). For a complex tool with 9 parameters, this lack of behavioral context 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, clear sentence that efficiently communicates the core functionality without any wasted words. It's appropriately sized and front-loaded, making it easy for an agent to quickly grasp the tool's purpose while leaving detailed parameter information to the schema.

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 tool with 9 parameters, no annotations, and no output schema, the description is insufficiently complete. It doesn't explain the output format (e.g., what the matrix looks like), error conditions, performance characteristics, or how it differs from sibling tools. The agent would need to rely heavily on trial and error or external knowledge to use this tool 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?

The description adds no parameter-specific information beyond what's already in the schema, which has 100% coverage with detailed descriptions for all parameters. While the description implies the tool uses coordinates and calculates matrices, it doesn't explain parameter interactions, defaults, or practical usage examples. Given the high schema coverage, a baseline score of 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 clearly states the tool's purpose with a specific verb ('calculate') and resource ('travel time and distance matrices between coordinates'), making it immediately understandable. However, it doesn't distinguish this tool from its sibling 'mapbox_matrix_by_places', which likely serves a similar purpose with different input methods, leaving room for improvement in sibling differentiation.

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 like 'mapbox_matrix_by_places' or other siblings such as 'mapbox_directions'. There's no mention of prerequisites, constraints, or typical use cases, leaving the agent with insufficient context to make informed decisions about tool selection.

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