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

With no annotations provided, the description must carry the full behavioral disclosure burden. It only states that the query is discarded, but does not reveal whether the tool performs any mutation, what it returns, how it handles the other eight parameters, or any side effects. This is a significant gap for a tool with no annotation safety profile.

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 brief and front-loaded, which is structurally sound, but it is under-specified. It omits essential details about return value and parameter scope, making it too sparse to be considered appropriately concise; it is more under-specified than concise.

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 9 parameters, no annotations, and no output schema, this description is grossly incomplete. It does not explain the output format, which parameter is the primary input, or how the other parameters relate. An agent cannot correctly invoke this tool based on the provided description.

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 each parameter has a documented purpose. However, the description adds no extra meaning beyond the schema and creates confusion by implying only the 'query' parameter is relevant while the schema lists many other parameters that may also be valid inputs. It fails to clarify which parameter represents the 'search query' or whether the tool counts characters for all provided parameters.

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 verb and resource ('Count characters in a search query'), but the 9-parameter schema includes many unrelated fields (ref, url, city, etc.) that are not obviously search-related, creating ambiguity about the tool's true scope. It does not distinguish itself from sibling counting tools like hn-front-count or memory-key-count, which could also count strings.

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 on when to use this tool versus alternatives. The description does not mention any selection criteria, exclusions, or context where this tool is preferred, leaving the agent without direction.

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