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

With no annotations, the description carries the burden and does well: it discloses the LaTeX-source requirement, the on-demand parse latency for out-of-library papers, and a strong fidelity guarantee ('nothing is summarised or inferred; every line is the paper's own'). It does not say what happens when a paper has no LaTeX source or how errors surface.

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 sentences, front-loaded with what the tool returns before the operational caveats. The opening phrase 'Everything Keystone reads out of one arXiv paper' is slightly branded/abstract, but otherwise every sentence earns its place.

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 no output schema, the description must characterize the return, and it does so in detail by listing the citation relationships and assumption provenance categories. Gaps are minor: no error/edge behavior for non-LaTeX papers and no sense of output volume or pagination.

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% and both parameters are documented in-schema, so the baseline is 3. The description adds interpretive color for the enum values by explaining what 'citations' (adopts/extends/disputes/measures against) and 'assumptions' (cited, own evidence, or none) mean, but never maps these to the include parameter explicitly.

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 one arXiv paper) and enumerates the output categories — adopts, extends, disputes, measures against, stated assumptions. It implies single-paper scope versus library-wide siblings, but never names list_disagreements or search_library, so sibling differentiation is left to inference.

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?

Gives a clear applicability condition: works for any arXiv paper with LaTeX source, and papers outside the library are parsed on demand with a few seconds of latency. What is missing is any explicit steering between this tool and list_disagreements/search_library.

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