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

readOnlyHint=true already tells the agent this is a safe, non-mutating read, so the description need not restate that. It adds mild value by noting the requirement that the address be 'owned' and that the return is a public deep link, but says nothing about error behavior for invalid or unowned codes.

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?

A single tight sentence with the verb and outcome front-loaded; nothing extraneous and no 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?

For a one-parameter read tool with no output schema, the description covers the essential input (an owned code) and output (public deep link). It omits failure cases (invalid format, unowned code) and how the link is produced, leaving minor 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?

Only one parameter, and the schema conveys its format via the ^[1-9]{9}$ pattern even though schema description coverage is 0%. The description matches the parameter to an 'owned address code', adding a little semantics about ownership scope, but no format or sourcing guidance.

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 ('Return') and a specific resource ('public deep link for an owned address code'), which is distinct from the create/delete/list/patch siblings. It stops short of explicitly contrasting itself with those siblings, but the fetched-artifact framing 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?

Usage is implied by the phrase 'owned address code' (the caller must own the address), but there is no explicit when-to-use, when-not-to-use, or naming of an alternative tool. An agent can infer the scenario, but nothing routes it definitively.

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