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

The phrase 'Query discarded' discloses that the input is not retained after the call, and the query parameter description repeats 'discarded after the length check.' However, the description does not explain the return value, side effects, or what happens if the query is absent, leaving significant behavioral details unspecified.

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 terse and front-loads the main purpose in the first sentence. The second sentence is a fragment but contributes a transparency note; no redundant wording is present.

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 a tool with no output schema and no annotations, the description is incomplete: it never states the result format (e.g., an integer character count) and never explains the unusual list of optional parameters. It leaves the agent to guess the behavior when query is omitted or when other params are supplied.

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 parameter descriptions carry most of the semantic weight; the query parameter is described as 'Search text; discarded after the length check.' The main description adds the notion of counting characters, but does not clarify why the other eight parameters exist or whether they are ignored, limiting added value.

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 core action: 'Count characters in a search query.' It names the resource (a search query) and the operation (counting characters), which is enough to distinguish it from most sibling tools. The following 'Query discarded' adds a small ambiguity but does not obscure the purpose.

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 usage guidance is provided. The description never says when to use this tool instead of alternatives like memory-key-count or other shape/count tools, and it does not mention prerequisites or typical call patterns.

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