user_timeline

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

No annotations are provided, so the description carries the full burden. It does disclose the read-only nature ('Read') and the count range constraint ('count 1-60'), but omits pagination behavior and auth requirements. Useful but incomplete for a no-annotation tool.

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?

Three short, front-loaded clauses with no filler; the core purpose leads and constraints follow. Efficient, though its extreme terseness is what leaves the pagination parameters unexplained.

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 five parameters at 0% schema coverage and no annotations, the description is too sparse: the ID-based pagination fields (max_id, since_id, page) are essential to calling this correctly and are never described. An output schema exists, so return values need not be covered, but the input side remains under-specified.

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 0%, so the description must compensate for all five parameters. It clarifies user_id (empty = authenticated user) and count (1-60), but leaves page, max_id, and since_id entirely undocumented, and these cursor parameters are non-obvious without explanation.

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 user's statuses'), which clearly maps to a timeline-fetch tool. It does not explicitly differentiate from close siblings like home_timeline or search_user_timeline, but the user_id default hint gives enough to separate it from the authenticated-user variants.

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?

'user_id empty = the authenticated user' implies when to use it for self vs. another user, which is genuine contextual guidance. However, there is no explicit when-to-use/when-not guidance relative to siblings such as home_timeline or mentions.

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