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

With no annotations provided, the description must carry the full burden of behavioral disclosure. It mentions that 'Values discarded,' which is one behavioral trait, but says nothing about side effects, permissions, return format, or what happens with the non-json parameters. This is a significant gap for a tool that accepts many inputs.

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 a single sentence, which is efficient, but it is under-specified for a tool with 9 parameters and no annotations. It lacks essential front-loaded context about what the tool does with the various inputs, making it more under-specification than conciseness.

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?

Given the tool's complexity (9 parameters, no annotations, no output schema), the description is woefully inadequate. It does not explain the purpose of the tool in relation to its many parameters, does not state return values, and does not address edge cases or error behavior. An agent cannot reliably determine how to call this tool correctly based on the current description.

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 description coverage is 100%, so each parameter is already documented in the schema. The description adds nothing beyond the schema's own per-parameter notes. Baseline of 3 is appropriate because the schema does the heavy lifting, and the description doesn't contradict or enhance it.

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 clear verb and resource ('Count keys in a JSON object'), but it fails to clarify how this relates to the 8 other parameters in the schema. The presence of params like ref, url, city, and host suggests a broader scope that the description ignores, creating ambiguity about the tool's actual function.

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 guidance on when to use this tool versus any of its 27 siblings. The description provides no context, no exclusions, and no alternatives, leaving the agent to guess based solely on the name and schema.

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