ChartMogul 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 and does so effectively. It discloses key behavioral traits: the default limit of 20 items, a warning to avoid excessive token usage, the response structure (contact objects with detailed fields), pagination behavior (cursor/has_more), and filter examples. It does not cover aspects like rate limits or authentication needs, but provides substantial operational context.

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 sized and front-loaded, starting with the core purpose and immediately following with critical warnings and details. Every sentence earns its place, though the structure could be slightly more organized (e.g., separating warnings from response details).

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 (list operation with filtering and pagination), no annotations, and no output schema, the description is largely complete. It covers purpose, parameters, behavior, and response format. However, it lacks explicit error handling or authentication context, which could be beneficial.

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 schema description coverage is 0%, so the description must compensate, which it does excellently. It explains all three parameters: 'email' and 'customer_external_id' as filters with examples, and 'limit' with its default value and a usage warning. This adds crucial meaning beyond 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 clearly states the tool's purpose with a specific verb ('List') and resource ('contacts'), explicitly noting they are 'individuals associated with customers'. It distinguishes from siblings like 'retrieve_contact' (singular) and 'list_customers' (different resource).

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 clear context for usage by mentioning filtering capabilities (email, customer_external_id) and pagination (cursor/has_more). However, it does not explicitly state when to use this tool versus alternatives like 'search_customers' or 'retrieve_contact', nor does it mention any exclusions or prerequisites.

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