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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so safety is covered. The description adds real value beyond that: it discloses the default filter behavior (open items unless told otherwise) and what each row carries — responsible person, deadline, and overdue flag — which tells the agent what it will get back and how to interpret it.

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?

A single dense sentence, front-loaded with the bracketed scope tag and the resource definition before the behavioral details. Every clause carries information, though the parenthetical enumeration of task types is slightly heavy.

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?

Return values are covered by the output schema, so no explanation is needed there. But for a 5-parameter filtered list with only 20% schema coverage, the description leaves the meaning and accepted values of kind, assignee and thread_id entirely undetermined, which is a substantive gap for correct invocation.

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?

With 5 parameters at 20% schema description coverage, the description must carry the burden, and it largely does not. Only the 'open by default' phrasing maps loosely to the status enum; kind, assignee, and thread_id are unexplained in both schema and description, leaving the agent guessing at valid values and 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 names a specific resource — the support desk's internal tasks — and enumerates the concrete subtypes (warranty cases, callbacks, bank refunds, claims, quotes), so an agent can tell it apart from case-creation siblings like warranty_case_open or callback_task. The verb 'list' is only implied via 'open by default' and the tool name, not stated outright.

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?

'Open by default' communicates the implicit default filter, and 'Works on: Support desk' scopes the operating context. However, there is no explicit guidance on when to call this versus looking up a single case, nor any mention of the alternatives among the many sibling list/opening tools.

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