Amazing Marvin MCP

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

With no annotations provided, the description carries full burden but offers minimal behavioral insight. It mentions 'efficient API filtering' but doesn't disclose critical traits like whether this is read-only, requires authentication, has rate limits, returns paginated results, or what happens with invalid dates. This is inadequate for a tool with potential data access implications.

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 appropriately concise with two sentences: one stating the tool's purpose and efficiency note, another detailing the parameter. It's front-loaded with the core function. The 'Args:' section could be slightly more integrated, but overall there's minimal waste.

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 complexity (filtered data retrieval), lack of annotations, and no output schema, the description is incomplete. It doesn't explain what 'completed tasks' entail, the return format, error handling, or authentication needs. This leaves gaps for an agent to use the tool effectively in varied contexts.

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 significant value beyond the input schema, which has 0% description coverage. It explicitly defines the 'date' parameter's purpose, format ('YYYY-MM-DD'), and provides an example ('2025-06-13'), fully compensating for the schema's lack of documentation. This is essential for correct tool invocation.

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 action ('Get completed tasks') and resource ('for a specific date'), distinguishing it from siblings like 'get_completed_tasks' (which lacks date filtering) and 'get_tasks' (which may include incomplete tasks). However, it doesn't explicitly contrast with all similar tools like 'get_due_items' or 'get_daily_focus', preventing a perfect score.

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 implies usage context through 'efficient API filtering' and the date parameter, suggesting this is optimized for date-specific queries. However, it lacks explicit guidance on when to use this versus alternatives like 'get_completed_tasks' (no date filter) or 'get_productivity_summary_for_time_range' (broader time range), leaving some ambiguity.

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