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

The description offers a single behavioral note—'Title discarded after the call'—which suggests the input is not persisted. But this note refers to a 'title' that is absent from the schema, and nothing is disclosed about read-only status, network dependency, error behavior, or return format. With no annotations present, the description carries the full burden and fails to cover these essentials.

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 description is only two sentences and front-loads the main purpose effectively. However, the second sentence about the title being discarded is confusing and redundant given the schema mismatch, so not 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?

For a validation tool with seven generic parameters, no annotations, and no output schema, this description is critically incomplete. An agent cannot determine which parameter carries the Wikipedia title, what response to expect, or when this tool is appropriate, making successful invocation nearly impossible without external knowledge.

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%—every parameter has a description—so the baseline is 3, but the tool description actively misleads by referring to a 'title' parameter that does not exist in the schema. It provides no mapping from the stated purpose to any of the seven actual parameters, undermining the agent's ability to construct a correct call.

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 states a concrete action and resource: 'Check whether a Wikipedia title exists.' However, the input schema contains no 'title' parameter—instead there are unrelated fields like 'ref', 'url', and 'city'—so the core purpose does not map cleanly onto the tool's actual inputs. It also does not differentiate this from the many sibling '-ok' validation tools.

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?

No guidance is given about when to reach for this tool versus alternatives like browser-url-ok, file-path-ok, or web-fetch. There are no context conditions, exclusions, or mentions of a sibling tool for different input types.

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