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

Because no annotations are provided, the description carries the full burden of behavioral disclosure. It only says 'Expression discarded,' which is cryptic and inconsistent with the schema. It does not clarify side effects, output format, or what the tool actually does with the inputs, and the mention of 'a+b' contradicts the parameter list. This is severely insufficient for a tool with zero annotation coverage.

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 extremely short (one clause) and front-loaded, but it is concise at the expense of clarity. It omits all substantive information and introduces a misleading purpose. Conciseness alone is not valuable when it obscures the tool's real function; a longer, accurate description would be preferable.

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 tool with 9 parameters, no output schema, and no annotations, the description is completely inadequate. It fails to explain the tool's true behavior, the role of each parameter, or the return value. The mismatch between description and schema leaves an agent with no reliable information to decide when and how to invoke it 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?

The schema has 100% description coverage for its 9 parameters, each with a short explanation (e.g., 'Git ref name; discarded after the shape check'). The tool description adds no information about parameters, so it does not enhance understanding. The baseline of 3 applies because the schema already documents all parameters adequately, even though the description itself is useless here.

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 claims the tool evaluates a+b style arithmetic, but the input schema contains 9 unrelated parameters (ref, url, city, feed, etc.) with no arithmetic operands. This is actively misleading and fails to convey the actual purpose (which appears to be a generic shape-check tool given sibling names like domain-shape and file-path-ok). The description does not distinguish this from any sibling and provides a false resource and verb.

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 provided on when to use this tool versus alternatives. It does not state any context, prerequisites, or exclusions, and it does not reference any sibling tools. In fact, the description suggests a use case (arithmetic evaluation) that has no basis in the schema, which could lead an agent to invoke it incorrectly.

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