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

No annotations are provided, so the description carries the full behavioral burden. It hints at a 'shape check' with discarded values but doesn't disclose whether the tool mutates, has side effects, or what it returns. The phrase 'value discarded' is a fragment of behavior disclosure, not a coherent description of what the call does.

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?

It is short, but it is under-specified rather than concise. The single fragment is not front-loaded with the actual purpose and reads like a mislabeled header field, not an action.

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?

A 9-parameter tool with no annotations, no output schema, and a description that doesn't state what the tool does leaves the agent with no basis for correct invocation. The description is functionally inadequate for a tool of this complexity.

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 100%, so each of the 9 parameters is documented in the schema itself. The description contributes nothing beyond name repetition. Baseline 3 applies because the schema does the heavy lifting; the description adds no meaning.

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 'Proxy-Authenticate scheme token, value discarded' names a specific-but-arbitrary header string and never states the tool's actual purpose. The parameter list (ref, url, city, feed, host, json, path, zone, query) suggests a normalization/shape-check utility, but nothing in the description explains what the tool does. It is effectively misleading about the tool's job.

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 on when to use this tool, when not to, or which sibling it replaces. Given ~30 closely-named siblings (validate-json, normalize-url, timezone, geo-hint, etc.), the absence of any routing information is a serious problem.

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