Amazing Marvin MCP

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

With no annotations, the description carries the full burden of behavioral disclosure. It implies a read-only operation but doesn't specify if it requires authentication, returns paginated results, or handles errors. The phrase 'Get time tracking data' suggests retrieval, but lacks details on data format, rate limits, or side effects, leaving significant gaps.

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 front-loads the core purpose without unnecessary words. However, it could be more structured by including key details like data scope or usage context, but it avoids redundancy and is appropriately sized for its limited content.

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 moderate complexity (retrieving data for tasks), no annotations, no output schema, and low schema coverage, the description is incomplete. It doesn't cover return values, error handling, or behavioral traits, making it inadequate for the agent to reliably invoke the tool without additional context.

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 mentions 'specific tasks' but doesn't elaborate on the 'task_ids' parameter beyond what the schema indicates (an array of strings). With 0% schema description coverage, it fails to compensate by explaining what task IDs are valid, their format, or how many can be included, adding minimal value over the bare schema.

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 as retrieving time tracking data for tasks, which is clear but vague. It specifies the resource (time tracking data) and scope (tasks) but lacks detail on what data is included (e.g., duration, timestamps) and doesn't distinguish from siblings like 'time_tracking_summary' or 'get_currently_tracked_item'.

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. It doesn't mention prerequisites, such as needing existing tasks with time tracking data, or compare it to siblings like 'get_tasks' or 'time_tracking_summary', leaving the agent to infer usage from context alone.

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