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

With no annotations at all, the description carries the full burden. It does disclose useful behavioral facts: results are ordered chronologically, scope is the user's personal library rather than the global corpus, and cost is 'Free · 1 credit'. It omits result limits, pagination, and whether ordering is ascending or descending.

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 sentences, front-loaded with the core purpose, then the use case, then the cost tag. Nothing is redundant, though the credit tag is bracketed metadata rather than describing the tool's behavior.

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 3-parameter tool with no output schema and no annotations, the definition covers purpose, use case, and cost but leaves the `kind` parameter and result-set size/ordering direction unexplained. An agent could call it, but might misuse or omit `kind`.

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 33% — only `since` is documented (YYYY-MM-DD). The description explains `query` as free-text, but `kind` is a bare untyped, un-enumerated string with no meaning given anywhere, and the description does not compensate for that gap as a low-coverage schema requires.

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?

"Chronological list of papers matching a free-text query" gives a specific verb (list), resource (papers), and scope (your personal library, chronological ordering), which distinguishes it from unordered search siblings. It stops short of naming a specific sibling to contrast against, so differentiation is implied rather than explicit.

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 description explicitly names a use case — 'how has X evolved' style questions — which tells an agent when this chronological view beats a plain search. It offers no negative guidance or named alternatives, so the agent must infer when not to use it.

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