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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so safety is covered. The description adds useful behavioral detail beyond those annotations: the returned content is Markdown, citation-ready, and includes canonical URL, dates, topics, body text, and only public images. It does not mention error behavior, but this is not a critical omission given the annotations.

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?

A single, dense sentence that leads with the core action and output format, then enumerates the included content without elaboration. Every phrase earns its place and there is no redundant filler.

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?

The tool has only two parameters and no output schema, so the description needs to convey the shape of the return value. It does so with a solid enumeration (canonical URL, dates, topics, body text, public images). It could note behavior for invalid/unpublished slugs, but the description is sufficient for a competent agent to select and invoke the tool correctly.

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 description coverage is 50%, with slug having no description. The description compensates partially by explaining that slug identifies the article and locale is the optional language tag. It also reveals that the output is language-dependent ('optional language tag'), adding meaning beyond the raw schema. The pattern/default details are already in the schema, so no need to repeat them.

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 ('Return') and resource ('one published Aperture Journal article') with the key identifier (slug) and optional locale. The phrase 'citation-ready Markdown representation' adds a clear, distinct deliverable that separates it from list_articles and other get_* siblings.

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 context is clear: use this to retrieve a single article by slug, optionally in a specific language. It does not explicitly mention when to prefer list_articles or fetch, but the singular-article-by-slug framing strongly implies the intended use case, with no misleading guidance.

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