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

readOnlyHint=true already tells the agent this is a safe read, so the description owes context beyond that and delivers almost none. 'Price: free' is ambiguous — it could describe the tool's cost or a value in the returned data — and there is no mention of which port is read, whether results are cached, or the shape of the response.

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?

It is short with no filler, and the content list is front-loaded, but the trailing fragment 'Price: free' is cryptic and reads as an afterthought rather than useful information. Two sentences, but the second does not clearly earn its place.

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 parameters and no output schema, the description must explain how the target port is determined and what the response covers; it lists four content categories but never resolves the implicit 'which port' question. It is minimally adequate for a simple read tool but leaves a real gap.

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?

The tool takes zero parameters and the schema is trivially complete, so there is nothing for the description to clarify about inputs. Baseline 4 applies for a no-parameter tool.

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 enumerates the content returned (offerings, costs, logs, rules) which suggests a read of port/customs metadata, but never states a verb or the resource unambiguously — 'port' is undefined and the title mixes 'customs' with 'port'. It does not distinguish this from siblings like stall_detail or niche_detail, which likely return similar descriptive payloads.

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?

There is no statement of when to call this versus the many sibling lookup tools (stall_detail, niche_detail, find, beacon_check). No prerequisites, no exclusions, no situational context is given beyond the implicit 'you want port facts'.

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