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

Adds real behavioral context beyond the annotations: the returned proxy key is 'shown once', and the proxy is addressed with a Bearer key, plus the account-key requirement. Annotations already cover the mutation safety profile (readOnlyHint=false, idempotentHint=false), so the extra auth and one-time-secret details are the valuable additions.

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?

Four tight sentences, front-loaded with the action, then the return values, then the client wiring, then the auth prerequisite. No filler or repetition of schema content.

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?

With no output schema present, the description usefully discloses the return payload (proxy id, MCP URL, one-time key) and the auth requirement. It omits retry/non-idempotency implications for a creation tool and any limits or naming collision behavior, but is otherwise sufficient to call 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 the schema already documents all four parameters including the mode enum and its dry-run guidance. The description adds nothing about parameter formats, so the baseline of 3 applies.

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?

Specific verb ('Create') plus a concrete resource ('hosted agentguard proxy in front of an MCP server'), which no sibling tool duplicates. An agent can distinguish this from agentguard_set_policy or agentguard_get_run without opening the schema.

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 states the prerequisite ('Requires an account key') but gives no explicit when-to-use versus alternatives and no exclusion conditions. Usage is only implied by the fact that none of the siblings perform proxy creation.

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