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

No annotations are provided, so the description must carry the full behavioral disclosure. It only states that values are discarded, which is a minor trait. It does not mention error handling, side effects, permissions, or what happens with invalid input. For a tool with no annotations and a complex parameter set, this is insufficient.

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 concise—two short sentences with no filler. The main action is front-loaded. However, given the parameter complexity, the brevity may be a drawback, but conciseness itself is good. It earns a 4 for being succinct and direct.

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?

The tool has 9 parameters and no output schema, yet the description explains only the core action without any guidance on how the parameters are used or what the return value looks like. It does not clarify which parameter is the JSON object or why the other parameters exist. This is severely incomplete for an agent to call 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?

Schema description coverage is 100%, so every parameter has a description in the schema. The tool description does not add any meaning beyond the schema—it does not explain how the diverse parameters relate to the stated purpose of counting keys. With high schema coverage, the baseline is 3, and the description adds no extra value, so a 3 is appropriate.

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 action and target ('Count keys in a JSON object') and adds the behavioral note 'Values discarded.' However, the tool name 'memory-key-count' and the diverse parameter list (ref, url, city, feed, host, json, path, zone, query) create confusion about what the tool actually does, and the description does not differentiate it from siblings like validate-json or web-fetch. The core purpose is understandable but the parameter mismatch undermines clarity.

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 description provides no guidance on when to use this tool versus alternatives. It does not mention any conditions, prerequisites, or exclusions. An agent would have no idea whether this tool is appropriate for counting keys in a JSON payload or for some other operation involving the listed parameters.

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