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

With no annotations, the description carries the full transparency burden, but it only discloses that the query is discarded after the length check. It does not explain whether the unrelated schema parameters (url, city, path, etc.) affect behavior or what side effects, if any, occur.

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 with no redundant wording. The behavioral note 'Query discarded' is compact, though it could arguably be separated into a behavioral section if more structure were used.

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 simple core purpose, the description omits helpful context such as whether the count includes whitespace or Unicode characters, and it does not clarify why eight unrelated parameters are present. Without an output schema, the exact return value is also left implicit, making the tool incomplete for an agent to use confidently.

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?

Although schema description coverage is 100%, most parameter descriptions are semantically disconnected from the stated purpose of counting characters in a search query. The extra parameters (e.g., 'HTTPS URL to normalize or cite', 'JSON text to validate') imply unrelated functionality and could confuse an agent; only the query parameter's description aligns with the tool 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 the tool's function with a specific verb and object: 'Count characters in a search query.' It does not, however, explicitly contrast it with sibling count tools such as hn-front-count or memory-key-count, so it is clear but not maximally differentiated.

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 provided about when to use this tool instead of sibling tools or about what kinds of queries it is intended for. The only behavioral note, 'Query discarded,' hints that it is side-effect free but does not constitute usage guidance.

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