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

With no annotations, the description carries the full burden of behavioral disclosure. It states that the query is discarded, which is a useful data-handling note implying no persistence. However, it does not explicitly mention read-only status, return format, or other side effects, leaving gaps.

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 concise, consisting of two short sentences. It front-loads the core purpose and adds a behavioral note, making it appropriately sized for a simple tool.

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 exposes 9 parameters but the description only mentions 'search query', leaving ambiguity about how to use the other parameters. It does not specify that only the 'query' parameter is used or that others are ignored. There is no output schema, so the return format is unknown. The description is inadequate for a tool with this many parameters.

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 input schema provides 100% coverage for all parameters, so the schema already documents each parameter. The description adds no parameter-specific meaning, and the baseline of 3 is appropriate because the description does not clarify which parameter is the search query, though the schema does label 'query' appropriately.

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 clearly states the tool counts characters in a search query, using a specific verb and resource. It distinguishes from siblings like memory-key-count by the object being counted, though it does not explicitly name alternatives.

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 given on when to use this tool versus alternatives such as memory-key-count or hn-front-count. The description does not mention any exclusions, preconditions, or alternative tools.

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