get_timeline

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

Annotations already cover the safety profile (readOnlyHint, openWorldHint), so the description's real contribution is 'Billed per post returned' – a cost consequence the agent cannot see anywhere else and which should discourage oversized page requests. It adds nothing about auth or rate limiting beyond that, keeping it at 4 rather than 5.

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?

Four compact clauses, no filler, with the resource, the enum glossary, the default, and the billing constraint all front-loaded. Every sentence carries information an agent needs before calling.

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 an 8-parameter read tool with no output schema, the description names the resource, enumerates the type domain, states a default, and warns about per-post billing. What is missing is any hint of what a returned post/page looks like or how pagination_token chains pages, which the schema implies but never explains.

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 75%, and the description covers the biggest semantic gap: it defines each enum value of `type` (the only required param) and states that `user` defaults to the caller's own account. It adds nothing for `exclude`, `start_time`/`end_time` or pagination, which the schema already handles.

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 opens with a specific verb+resource ('Read a timeline') and enumerates every accepted type with a parenthetical meaning, so the agent knows exactly what is retrieved. It does not explicitly differentiate itself from the sibling get_posts, which is the obvious adjacent read tool, so it falls short of a 5.

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?

The type-by-type annotations ('home (your reverse-chronological home feed)', 'liked (posts a user liked)') effectively tell the agent which value to pick for which content need, and the defaulting rule for `user` is stated. There is still no explicit when-not or named alternative such as get_posts or search, 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.