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

Annotations already declare readOnlyHint, idempotentHint, non-destructive, and closed-world, so the safety profile is covered. The description adds only that returned URLs are absolute, plus an unexplained '[no key]' fragment whose meaning is unclear; it does not disclose whether both identifier params are needed or how multiple citations are ordered.

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?

The core statement is short and front-loaded, but the dangling '[no key]' fragment is cryptic noise that adds no actionable meaning and slightly muddies the message.

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?

An output schema exists, so return values need not be explained, but with both parameters undocumented and no guidance on path-vs-slug selection, the definition leaves the agent unable to confidently construct a call.

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 0% and the description says nothing about 'path' or 'slug' — it never clarifies whether they are alternatives, whether one is required, or what format each takes. With two undocumented identifier parameters, the description fails to compensate for the schema gap.

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 phrase 'The sources listed on one article, with absolute URLs' identifies the resource (citations for a single article) and the return shape, but there is no verb and no differentiation from siblings like get_article or related_articles. An agent can guess the intent, but it isn't stated as an action.

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?

There is no indication of when to call this versus get_article, fetch, or lookup_quote, and no prerequisites or alternatives are named. The agent must infer usage purely from the tool name.

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