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

With no annotations provided, the description carries the full burden of behavioral disclosure. It does disclose that the query is discarded, which is a key side effect (no retention), but it says nothing about the behavior of the other eight parameters, potential return format, or error cases. For a tool that appears to accept a wide variety of inputs, this is thin 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 concise: two short sentences that front-load the core purpose and immediately note the discard behavior. Every word earns its place; there is no fluff or redundancy.

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 description is incomplete given the tool's actual parameter surface. While the schema documents each parameter, the description does not explain why a tool named 'search-query-len' accepts ref, url, city, feed, host, json, path, and zone. This creates confusion about the tool's true scope. There is no output schema, so the return format is also unaddressed. For a tool with this many optional parameters, more context is needed to enable correct invocation.

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% – every parameter already has an individual description (e.g., 'discarded after the shape check', 'normalize or cite'). The tool description adds no extra meaning to the parameters beyond what the schema provides. Baseline of 3 is appropriate; the description does not compensate for any gaps because there are none.

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 specific verb ('Count') and a clear resource ('characters in a search query'), and explicitly notes the query is discarded. This is unambiguous and distinguishes it from the sibling tools (e.g., 'memory-key-count' or 'hn-front-count') which involve different inputs. The purpose is immediately clear.

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 does not provide any explicit guidance on when to use this tool versus alternatives, nor does it mention any exclusions or prerequisites. It implies a usage context (counting query length) but offers no comparative insight. Given the many sibling tools, this is a gap.

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