upsert_guardrail_mcp_server

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

Annotations already declare idempotentHint=true and destructiveHint=true, so the 'Repeating the same mapping is safe' line largely restates the idempotency annotation. However, the description adds genuine behavioral context beyond annotations: the partial-scope guarantee ('without changing mappings for other servers'), the guardrail prerequisite, and the run_on default. It does not spell out what an existing mapping is destroyed/replaced with, but for an annotated tool this is solid.

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 short sentences, front-loaded with the core action and scope before prerequisites and the sibling reference. Each sentence adds a distinct piece of information, though the idempotency line partly duplicates the annotation.

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 an output schema present, return values need not be explained, and the description covers purpose, scope, prerequisite, default behavior, and a discovery sibling. It is nearly complete for a 4-parameter upsert; only the exact effect on a pre-existing mapping is left implicit.

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 four parameters (including run_on's default) are already documented in the schema. The description's note that 'run_on defaults to both input and output' mirrors the schema default and adds no syntax or format detail. Baseline 3 is appropriate when the schema carries the parameter burden.

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?

States a specific verb+resource ('Create or replace one guardrail mapping for one MCP server') and immediately scopes it with 'without changing mappings for other servers,' which distinguishes it from the plural sibling replace_guardrail_mcp_servers. An agent can tell exactly what this does 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?

Explicitly directs the agent to 'Use list_guardrail_mcp_servers to inspect the current mapping set first' and states a prerequisite ('Requires a guardrail with target mcp_tools'). It stops short of explicitly contrasting when to pick this over replace_guardrail_mcp_servers, but the scoping clause strongly implies the choice.

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