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

With no annotations, the description carries the full safety burden and does so: it declares 'read-only' and 'client-agnostic' and specifies that results are 'read from the service's own metadata,' which explains why the assessment is authoritative. It does not cover failure modes, auth requirements for the underlying fetch, or rate limits, so it falls short of exhaustive disclosure.

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?

Two tight sentences; the return shape and status vocabulary come first, and the routing hint to connect_domain comes last where it belongs. Every clause adds information, with no restatement of the tool name or title.

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?

There is no output schema, but the description compensates by enumerating the return contents (each connectable resource plus readiness status plus the exact missing field) and by flagging the operation as read-only. An agent has everything needed to call this correctly and interpret the result.

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 schema description coverage is 100% ('Registrable domain, e.g. example.com'), so the schema already documents the input fully. The description adds no format, normalization, or validation nuance about the domain beyond what the schema states, so the baseline of 3 applies.

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?

Specific verb+resource: 'Given a domain, return each connectable resource it publishes with a readiness assessment.' It also enumerates the four possible statuses (ready | credentials-required | incomplete | broken), which pins down the semantics, and names the sibling connect_domain so it is distinguishable without opening sibling schemas.

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?

It names the alternative explicitly ('Use connect_domain when you know the client's capabilities') and gives the discriminating condition, which by implication is also the when-to-use condition for this tool (you don't yet know capabilities). discover_domain is not mentioned, but no inference is needed to choose between this and connect_domain.

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