CDP MCP Server

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

With no annotations provided, the description carries full burden for behavioral disclosure. It mentions the HTTP endpoint and that the update definition should be a JSON string, but fails to disclose critical traits: whether this is a destructive mutation (implied by 'Update' but not explicit), authentication requirements, rate limits, error handling, or what constitutes a valid 'updated definition'. For a mutation tool with zero annotation coverage, this leaves significant gaps in understanding the tool's behavior.

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 that directly address the tool's function and input format. It's front-loaded with the core purpose and avoids unnecessary verbiage. However, the inclusion of the HTTP endpoint (PUT /v2/{tenantId}/mailer/identifiers/{id}) is somewhat redundant for an AI agent that doesn't need low-level API 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 complexity (mutation operation with 3 parameters), lack of annotations, and 0% schema description coverage, the description is insufficiently complete. While an output schema exists (which relieves the need to describe return values), the description fails to compensate for missing behavioral context and parameter semantics. For a mutation tool in a system with many siblings, more guidance on usage and constraints is needed.

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?

Schema description coverage is 0%, meaning none of the three parameters (id, body, tenant_id) have descriptions in the schema. The description only vaguely references 'updated definition as a JSON string' which partially relates to the 'body' parameter, but doesn't explain what 'id' refers to (e.g., identifier of the mailer to update), the optional 'tenant_id', or the structure/constraints of the JSON body. It adds minimal value beyond the bare parameter names in the 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 action ('Update') and resource ('a mailer identifier'), which provides a specific verb+resource combination. It distinguishes from siblings like 'cdp_create_mailer_identifier' and 'cdp_get_mailer_identifier' by focusing on modification rather than creation or retrieval. However, it doesn't explicitly differentiate from other update tools (e.g., 'cdp_update_mailer_account') beyond the resource name.

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. It doesn't mention prerequisites (e.g., needing an existing identifier), when-not-to-use scenarios, or comparisons to sibling tools like 'cdp_get_mailer_identifier' for reading or 'cdp_create_mailer_identifier' for creation. The HTTP method (PUT) is noted but doesn't constitute usage guidance for an AI agent.

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