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

Annotations already declare destructive=true, idempotent=false and openWorld=true, and the description adds context the annotations cannot: the page is publicly reachable by anyone with the link, non-owned flow ids are silently dropped rather than erroring, unspecified fields are preserved on update, and the plan caps portal count. This is exactly the behavioral disclosure that goes beyond the structured hints.

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?

Six tight sentences, front-loaded with the create/update distinction, then constraints and update semantics. Nothing is padded and every sentence adds either routing or behavioral information.

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 7-param, no-output-schema mutation tool with full annotation coverage, the description covers public exposure, ownership constraints, merge semantics and quota. It stops short of describing failure modes or what is returned, but with no output schema that omission is minor.

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 coverage is 100%, so the baseline is 3; the description earns a bump by stating merge semantics on update ("fields that are not given keep their current value"), which tells the agent that omitting optional params will not clear existing values – behavior the schema's per-field descriptions do not convey.

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 ("Create a client portal, or update one") and immediately explains the upsert switch via portal_id, so the dual mode is unambiguous. It also defines what a portal is ("a public page that anyone with the link can open"), which cleanly separates it from siblings like list_portals and delete_portal.

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 clear mode-selection guidance (omit portal_id to create, pass it to update) and a hard constraint (only user-owned flows can be added; other ids are silently skipped). It does not name a sibling alternative or say when not to use this tool, which keeps it short of a 5.

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