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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds real context beyond that: the response field set, the permission-dependent rule that the full destination URL appears only for links you own, and plan availability. Remaining gaps (error behavior, whether results are cached/stale) are minor.

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 short sentences, front-loaded with the action and the return payload, then the ownership caveat, then plan availability. Nothing is redundant and no sentence could be dropped without losing information.

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, the description properly takes on the job of listing return values, and it covers the one surprising behavior (destination URL visibility tied to ownership). For a one-parameter read tool this is nearly complete; only error/not-found behavior is left unstated.

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 coverage is 100% and the single parameter is fully documented in the schema, including that a full short URL is accepted. The description's 'any short code' adds no syntax or format detail beyond that, so the schema does the heavy lifting — baseline 3.

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 uses a specific verb+resource ('Get the trust/safety scan result for any short code') and enumerates exactly what comes back (score, risk label, threat categories, destination hostname). It is clearly distinct from metadata siblings like get_link or get_link_stats, though it never names those siblings to make the contrast explicit.

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?

Usage is only implied by the purpose statement — an agent can infer this is the tool for safety checks, and 'Available on all plans' removes a plan-gating concern. There is no explicit 'use this instead of get_link when...' routing or statement of what happens for an unknown code.

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