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

With no annotations, the description carries the behavioral burden and it does disclose that the query is discarded. However, most of that disclosure is already present in the `query` parameter schema ('discarded after the length check'), so the tool description adds limited transparency beyond the structured fields and does not mention return value semantics or error behavior.

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. The primary action is front-loaded and the side-effect note is immediately after it.

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 has 9 parameters, none required, no annotations, and no output schema, but the description does not explain which parameter to use or what the output shape is. It also leaves ambiguous why the other optional fields exist, which hurts an agent's ability to invoke the tool 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?

Schema description coverage is 100%, so the baseline is 3. The phrase 'Count characters in a search query' does not add meaning beyond the schema, and it does not clarify how the 8 other optional parameters relate to the tool or whether `query` is the intended one.

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 verb and resource: count characters in a search query. It also adds a side-effect note that the query is discarded. It loses a point because it does not distinguish this from count/shape sibling tools or clarify which of the nine schema parameters constitutes the 'search query'.

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 use this tool instead of alternatives such as memory-key-count, hn-front-count, or normalize-url. The sentence 'Count characters in a search query' describes the operation but not the selection context or when-not-to-use conditions.

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