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

With no annotations, the description must carry the behavioral burden. It does disclose that the query is discarded, implying a stateless operation. But it does not describe the output format, error behavior, or how the tool handles the many non-query schema fields, so transparency is only partial.

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 only two short sentences and puts the primary operation first. Every word earns its place and there is no filler, making it exceptionally concise and well-structured.

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?

For an unannotated tool with no output schema, this is under-specified: it omits how the query is passed, what the count output looks like, and how to treat the seven other parameters. An agent reading it cannot confidently invoke the tool with the correct argument.

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?

Every schema property has a description, but none is labeled as a search query. The tool description refers to a 'search query' that is absent from the schema, which exposes ref, url, city, feed, host, json, and path. This introduces a phantom parameter rather than mapping the intended input.

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 names a specific action and object: 'Count characters in a search query.' This clearly signals a length-counting utility and distinguishes it from the sibling shape-validation tools. However, the phrase 'search query' does not correspond to any schema property, so the purpose is clear at a high level but not directly invokable.

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 about when to prefer this tool over alternatives, which of the seven schema parameters should be treated as the search query, or what prerequisites or limitations apply. The only additional sentence, 'Query discarded,' is a behavioral note, not usage guidance.

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