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

Annotations already cover the safety profile (readOnly, non-destructive, closed world), so the description's added detail is genuine value: a 200-message cap, oldest-first ordering, owner-only field visibility, and the required editor role. The note that client messages are plain text written without an account also preempts a common expectation about author identity.

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-loaded with the core verb and scope, and every clause adds information (visibility, owner fields, cap, ordering, unread count, permission). It is a single dense multi-clause sentence, which makes the latter half slightly harder to parse than a short bulleted breakdown would be.

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 carries the return-shape burden and succeeds: it enumerates all four returned pieces of information plus the message cap and ordering. An agent knows the required permission, the scope, and what it will get back before calling.

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% for the single parameter, so the schema already documents cardId as 'The task.' The description only restates the one-task scope and adds no format, ID-source, or lookup detail beyond the schema, so the baseline 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?

States a specific verb and resource ('Reads what the client portal means for one task') and enumerates exactly what is returned: client visibility, portal on/off for the owner, the task conversation, and unread count. This clearly separates it from project-level siblings like get_client_portal and generic get_task.

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?

Supplies real usage context: it is scoped to one task and requires the editor role on the project, and it clarifies that owner-only fields (portal state, conversation) are conditional. It never names an alternative sibling (e.g. get_client_portal) for the project-wide case, so the routing guidance is implied rather than explicit.

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