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

With no annotations, the description carries the full burden, and it delivers useful disclosure: the call is scoped to the authenticated user (implied auth requirement) and the response is enumerated as domain DTOs with named fields, plus a total count that signals paging. It omits rate limits, how limit/offset interact, and whether sorting/filtering have defaults. The return-shape disclosure goes well beyond what an unannotated tool usually offers.

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 sentences, operation stated first, return payload second. No filler, no restated title, and the capability summary ('optional search/filter/sort') is front-loaded.

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 6-parameter, unannotated, no-output-schema tool, the description covers purpose and response contents but leaves pagination semantics, filter precedence, and sibling differentiation unaddressed. An agent could invoke it, but would be guessing at several parameters.

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 only 17% across 6 parameters, so the description must compensate, and it largely does not. It generically mentions 'search/filter/sort' but never maps q, status, sort, dir, limit, or offset to behavior, defaults, or enum meaning. The vague keyword list overlaps the schema without adding actionable semantics.

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 gives a specific verb and resource ('List the authenticated user's subdomains'), which cleanly separates it from domains_get (single domain) and dns_zones (DNS zones). It also names the return payload, reinforcing what the tool is. It does not, however, explicitly contrast itself with the nearest siblings, so it stops short of a 5.

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?

'With optional search/filter/sort' implicitly tells the agent this is a browsable, filterable list, and 'the authenticated user's' scopes it to owned domains. There is no explicit when-to-use guidance, no statement of when to prefer domains_get or the DNS tools, and no exclusions.

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