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

Annotations already declare readOnlyHint and idempotentHint, so safety is covered. The description adds what annotations cannot: guest-accessible vs Standard+ gated content, and the auth endpoint URL. That is useful operational context, though it could note the response shape or that it is unauthenticated for guests.

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?

Three sentences, front-loaded with what the tool returns, followed by sibling routing and then access tiers. Dense but every sentence carries information; the auth URL could arguably be trimmed.

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?

No output schema exists, so the description must convey return content, which it does ('USD tiers and MCP entitlements'). Access-tier context completes the picture for a no-parameter read tool; only the envelope of the returned matrix is unspecified.

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?

Zero parameters, so there is nothing the description could usefully add; baseline 4 applies. The description correctly avoids inventing parameters.

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?

Names a specific resource (public plan matrix) with its source (/pricing) and contents (USD tiers and MCP entitlements), and explicitly separates it from the incident-monitoring siblings. An agent can tell instantly what it retrieves and what it does not.

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 routes outage-related questions to list_monitored_vendors and get_vendor_incidents, which is the strongest possible disambiguation against the sibling set. It stops short of stating when an agent *should* call get_pricing (e.g. before recommending a plan), but the exclusions are clear.

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