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

The description adds the behavioral detail that only provided fields are updated (partial update), which is valuable beyond the annotations (readOnlyHint=false, destructiveHint=false). However, it does not disclose other behavioral traits such as error handling, idempotency, side effects on connected resources, or what the response looks like. Given that annotations already indicate a non-destructive mutation, the description provides only modest additional disclosure.

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, tightly written sentence. It front-loads the essential information (patch operation) and the most important usage detail (send only changed fields). No filler or redundancy. It earns a perfect score for conciseness.

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?

For a patch operation with a complete schema and minimal annotation, the description covers the core requirement: perform a partial update using the create field set. However, it lacks additional context such as whether the server must already exist, what happens on failure (e.g., 404), or the shape of the response. An agent might need to infer these or look elsewhere. Given the tool's moderate complexity, a few more details would make it more complete.

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 100% – each parameter is already described (url, name, server_id, transport). The description adds context that only the provided fields are changed, but it does not add any new meaning to individual parameters beyond what the schema provides. The reference to create_mcp_server's field set is helpful but not strictly necessary since the schema is complete. Baseline of 3 is appropriate.

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 (patch/update), the target resource (existing MCP server), and the key behavior (partial update). It also references the sibling create_mcp_server for the field set, which distinguishes it from that creation tool and other update tools among the siblings.

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 explicit usage guidance by stating to send only the fields to change and pointing to create_mcp_server for the allowed field set. This tells the agent how to structure the request. However, it does not mention when not to use the tool (e.g., if the server does not exist or when full replacement is needed), so it lacks explicit exclusions or alternative routing.

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