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

With no annotations, the description carries the full behavioral burden. It does add genuine context not available elsewhere: caller gateway credentials, charges, and authorization determined by the gateway. However, it says nothing about pagination via the continue/blcontinue parameters, caps at 20 results per request, or ordering of results, which matter for correct invocation.

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 with the operation stated first and billing/auth context after; nothing is redundant. The gateway sentence is slightly boilerplate but earns its place by disclosing cost implications.

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 9-parameter tool with no output schema and no annotations, the description leaves real gaps: result pagination, the 20-per-request cap, and what a backlink entry contains are all unaddressed. The billing disclosure is helpful but does not complete the picture an agent needs to call this reliably.

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 baseline 3 applies. The description only implies that bltitle is the target article name; it adds no meaning about title formatting, namespace restriction, or how to page through results beyond what the schema already documents.

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?

"List English Wikipedia articles that link to the specified article" gives a specific verb (list), resource (Wikipedia articles), direction (that link to), and scope (English). An agent can distinguish this from wikimedia_get_external_links, which goes the other direction, without opening either schema.

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 inbound-link direction implies when to use it (finding referring pages, not outgoing citations), but the description never states prerequisites, when-not conditions, or names wikimedia_get_external_links as the alternative. Usage is inferable rather than stated.

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