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

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so the safety profile is covered. The description adds genuinely new behavior beyond that: pages are ordered, images may be absent ('where the archive holds one'), and a missing date yields neighboring issues with day deltas, with the gap named when over 14 days. It omits any statement about response size/pagination for large issues, which is the main remaining gap.

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?

Two dense sentences, front-loaded with the returned payload before the fallback behavior. Every clause carries information, though the second sentence is long and its clause chaining ('either side and how many days apart they are, and names the gap when...') takes a second read.

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 does a good job of naming the returned fields and describing the empty-result path, which is what an agent most needs. The only shortfall is that the multi-edition case (the third parameter) is not addressed in the description at all, and nothing is said about result size for a long issue.

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 the schema already documents all three parameters, setting a baseline of 3. The description adds meaning the schema does not: an inexact date does not simply fail, it falls back to nearby issues with day distances and a named gap beyond 14 days, which materially changes how the agent should choose the date value. The edition parameter is left to the schema.

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 names a precise resource ('the pages of one issue of a paper on a date, in order') and enumerates the fields returned (page id, image, reader link, holding library's copy), so the agent knows exactly what it gets. It is clearly distinguishable from get_page (one page) and search (discovery), and it also defines the no-issue case. No ambiguity about what the tool does.

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?

Explicit usage is given: 'Use to walk an issue, or to learn whether the archive holds a paper on a given day.' That tells the agent both a browsing and a holdings-lookup use case. It does not name alternatives (e.g., get_page for a single page, search for keyword lookup), so no exclusions are stated.

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