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 only mentions 'Query discarded' but does not disclose that the tool has eight other optional parameters with their own discard behaviors, nor does it explain what happens if multiple parameters are supplied. The behavioral contract is vague and potentially misleading given the schema's breadth.

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 brief and front-loaded with the primary purpose, achieving high conciseness. However, it is so terse that it omits necessary contextual information about the parameter set, which reduces its overall effectiveness despite the structural efficiency.

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 severely incomplete. It does not specify the output format, which parameters are relevant, or how the tool should be invoked correctly. The minimal text leaves too much to inference, making it inadequate for an agent to use reliably.

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 descriptions cover all 100% of parameters, each with clear intent, so the baseline is 3. The tool description adds minimal value, only reinforcing that the query parameter is used for length checking but not clarifying how the other parameters relate to the tool's purpose. It neither compensates for nor contradicts the schema.

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 action ('Count characters in a search query') and identifies the query resource, but it does not clarify how the tool relates to the nine parameters in the schema. It fails to indicate whether only the 'query' parameter is used or if the others are also handled, which creates ambiguity about the tool's actual scope.

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 the many sibling tools (e.g., normalize-url, validate-json). The description does not provide context, exclusions, or alternatives, leaving the agent without any decision support for selecting this tool.

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