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

Adds substantial behavior beyond the annotations: the check interval, the ~30s retry after a failure, marking the service down on the second consecutive failure, private-by-default creation, default notification channels, and named error outcomes (url_failing, plan_limit). This is exactly the operational context the readOnly/idempotent/destructive hints cannot convey.

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?

Front-loads the core purpose and the URL-validation/plan-limit constraints in one dense paragraph; every sentence carries operational information. It is on the heavy side, but no sentence is filler or a restatement of the name.

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 output schema, the description does the heavy lifting on failure modes (url_failing with reason, plan_limit with upgrade link) and preconditions, which is strong. The success response shape is left unspecified, a minor gap for a create tool.

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 schema carries the basics (baseline 3). The description still adds meaning not in the schema: the monitor is born private on default channels, `section` affects status page placement, and `confirmar` is tied to the url_failing path.

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 and resource ('Cria um monitor HTTP para uma URL pública') and scopes it to public https URLs, which cleanly separates it from atualizar_monitor and pausar_monitor. An agent knows exactly what object is being created without opening the schema.

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?

Gives concrete conditions: a failing URL is rejected unless `confirmar: true`, non-existent Tá Rodando addresses and the status page itself are refused, and plan ceilings return plan_limit. It does not explicitly name an alternative sibling or a when-not-to-use case, so it stops short of full routing guidance.

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