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

Annotations already declare readOnlyHint=true covering the safety profile, but the description adds real behavioral context: newest-first ordering, the default exclusion of activities, and the mutual-exclusivity constraint that before_id/after_id must be used one at a time.

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 what the resource is, then defaults, then filter values, then pagination, then the endpoint. Every clause earns its place with no filler.

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 read-only list tool with full schema coverage and no output schema, the description covers ordering, filtering, and pagination adequately. It does not mention the 'include' expansion parameter, but that parameter is documented in the schema, so the gap 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 baseline is 3, but the description goes beyond the schema by mapping filter values to intent ('NOTES' for internal notes only, 'MESSAGES' for messages, 'ALL' to include activities) and clarifying the cursor pagination constraint, adding meaning the terse schema descriptions do not.

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 ('Read a case's timeline') and enumerates the post types it returns (customer messages, agent replies, internal notes), which cleanly distinguishes it from kayako_get_case (case details) and kayako_list_cases (case list).

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?

It explains the default behavior (activities excluded) and how filters select subsets and how to paginate, which is useful implied usage guidance. However, it never explicitly says when to choose this tool over siblings such as kayako_get_case or kayako_search, so alternatives and exclusions are left to inference.

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