TimeChimp MCP Server

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. While 'Update' implies a mutation operation, the description doesn't address critical behavioral aspects: whether this requires specific permissions, if it's idempotent, what happens to fields not provided (partial vs. full updates), error conditions, or rate limits. For a mutation tool with 11 parameters and no annotation coverage, this is a significant gap in transparency.

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 consists of a single, efficient sentence: 'Update an existing expense.' It's appropriately sized for the tool's purpose, with zero wasted words. The structure is front-loaded with the core action, though there's no additional context to structure beyond this minimal statement.

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 (11 parameters, mutation operation, no output schema, and no annotations), the description is insufficiently complete. It doesn't explain what fields can be updated, how partial updates work, what the response looks like, or error handling. For a mutation tool with rich input schema but no output schema or annotations, the description should provide more contextual guidance to help the agent use it correctly.

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 input schema has 100% description coverage, with each parameter well-documented in the schema itself (e.g., 'id' as 'Expense ID', 'date' with format specification). The description adds no parameter information beyond what's already in the schema. According to scoring rules, when schema_description_coverage is high (>80%), the baseline is 3 even with no param info in the description.

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 'Update an existing expense' clearly states the verb ('Update') and resource ('expense'), making the basic purpose understandable. However, it doesn't differentiate this tool from sibling tools like 'update_expense_client_status' or 'update_expense_status', which also update expense-related data but with different scopes. The description is adequate but lacks 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. With siblings like 'update_expense_client_status' and 'update_expense_status' that handle specific aspects of expense updates, the agent receives no indication that this tool is for general expense field updates rather than status changes. There's also no mention of prerequisites or when not to use it.

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