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

There are no annotations, so the description carries the full burden of behavioral disclosure. It does disclose that the query is 'discarded,' which is useful, but it omits other important behaviors: return format, error handling, whether only the query parameter is used, and whether the other eight schema fields are ignored. For a tool with no annotations, this is thin.

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 two short sentences with no filler. 'Count characters in a search query' states the core operation, and 'Query discarded' adds a meaningful behavioral note. Every word earns its place.

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 nine optional parameters, no output schema, and no annotations, this description is not complete enough. It does not explain what the tool returns, which parameter to use, or why the schema contains fields like url, city, feed, and host. An agent could easily misuse the tool by passing the wrong parameter.

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 the schema already documents each of the nine parameters in detail. The main description adds little beyond aligning 'search query' with the query parameter. It does not clarify which parameter an agent should actually populate or that the other parameters appear unrelated to the stated purpose.

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 a specific action and resource: 'Count characters in a search query.' It is not a tautology and the resource ('search query') differentiates it from sibling count/validation tools. However, it does not explicitly distinguish itself from similar siblings like memory-key-count or hn-front-count.

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 the many sibling shape/validation/count tools. It does not mention conditions, exclusions, or alternatives. An agent is left to infer usage from the name and description alone.

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