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

Annotations already establish readOnly/idempotent/non-destructive safety. The description adds real behavioral value: it does NOT bypass restrictions, does NOT execute transactions, and unknown evidence yields no recommendation. This is meaningful edge-case disclosure beyond the annotations.

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 core action, followed by scope limits and the failure behavior. Every sentence earns its place with zero filler.

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, and the description omits the return shape beyond 'access restrictions' and 'a route'. With 5 parameters at 0% schema coverage and no output schema, more detail on the response and the cost/route semantics would be expected. Adequate but with clear gaps.

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 0%, so the description must carry parameter meaning, but it doesn't mention action, capabilities, budget_usd, or user_agent at all. The enums self-document somewhat, leaving a real gap for `capabilities` and `budget_usd` semantics (e.g., how budget influences the 'lowest observed-cost' route).

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 ('Preflight') and resource ('public HTTPS URL'), and the outcome ('Returns observed access restrictions and the lowest observed-cost eligible route'). No sibling tools exist, so no differentiation is needed, but the purpose is unambiguous.

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?

Tells the agent the tool is a preflight step 'before fetching', which implies sequencing, but gives no explicit when-not-to-use guidance or alternatives. Usage context is only loosely implied.

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