panelica_domains_post_v1_domains_id_subdomains

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

The description adds the required scope (domains:write) and the explicit confession 'Mutating: changes server state,' which is consistent with readOnlyHint=false, so there is no contradiction with annotations. However, it discloses no side effects or postconditions (e.g., DNS changes, propagation, whether the subdomain is immediately usable) and, given the open body schema, could have been more transparent about what the mutation requires.

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?

The description is compact and front-loaded: the purpose leads, followed by short single-purpose lines for HTTP method, category, scope, and mutation flag. The HTTP line partially duplicates the route encoded in the tool name, but the structure is clean and every remaining line earns 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?

For a mutating creation tool with an undeclared open body schema and no output schema, this description is too thin. An agent has no way to construct a valid request body, no indication of what fields are required, and no statement of what a successful call returns or changes. The scopes and mutability flags help, but the critical invocation detail is missing.

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 100%, so the baseline is 3. The description adds no meaning beyond the schema: it does not hint what the body should contain, and the schema itself punts ('Schema not statically declared — see API docs'). With an open additionalProperties body, a one-line hint about the expected payload (e.g., subdomain name) would have materially helped.

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 states a specific verb and resource — "Create subdomain" — and the HTTP line confirms the exact route (POST /v1/domains/:id/subdomains). It is unambiguous against siblings like the GET subdomains list or DELETE subdomains endpoints, though it does not explicitly name a sibling it differs from.

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?

No guidance is given on when to use this tool versus alternatives, no prerequisites (e.g., domain must exist), and no hints about what constraints apply. 'Required scopes: domains:write' is an auth prerequisite rather than usage direction, and there is no exclusion or alternative routing information.

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