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

Annotations already indicate this is a write operation (readOnlyHint=false, destructiveHint=false). The description adds the non-secret headers constraint, which is also present in the schema, and the purpose. It does not disclose response behavior, idempotency, or any side effects beyond creation. Given annotations cover the basic safety profile, the description adds modest value but no deeper behavioral 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 a single, well-structured sentence that front-loads the action and resource, then adds a constraint and purpose. No redundant or filler content; every word earns its place.

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 create operation with no output schema, the description conveys the essential purpose and a key constraint. It does not elaborate on post-creation steps (like attaching tools) but that is covered by sibling tools. The tool's complexity is moderate, and the description is sufficient for an agent to understand when and how to 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?

Schema description coverage is 100%, so all six parameters are well-documented in the schema. The description's mention of 'non-secret headers only' aligns with the schema's custom_headers description but does not add new parameter-specific meaning. With high coverage, a 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 verb 'Register' and the resource 'a new MCP server', and specifies the scope 'in the org'. It also adds the purpose 'so its tools can be attached to agents', which distinguishes it from sibling tools like attach_mcp_server (which attaches an existing server) and update_mcp_server (which modifies an existing one).

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: it is for creating a new server, and the purpose of enabling attachment to agents implies the subsequent workflow. However, it does not explicitly state when NOT to use this tool (e.g., 'if the server is already registered, use attach_mcp_server instead'). The implied usage is strong but not explicit.

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