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

The description explicitly discloses that the query is discarded, which is a useful hint that the operation is non-persistent. However, with no annotations, it does not clarify the return format, character-counting semantics, or edge-case 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 extremely concise: two short sentences, each earning its place. The action is front-loaded and the discarded-input note adds behavioral value without filler.

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 is not safely invocable from the provided description: the central input ('search query') is absent from the schema, there is no output schema, and no annotations clarify behavior. An agent cannot determine which of the seven parameters to populate or what the response will be.

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?

The description refers to a 'search query', but the input schema exposes the properties ref, url, city, feed, host, json, and path, with no 'query' field. The description adds no mapping between the described purpose and any schema parameter, making the tool effectively uninvocable from the given information.

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 meaningful behavioral note ('Query discarded'). However, it does not differentiate from sibling tools and the notion of a 'search query' is not represented in the input schema, which slightly weakens practical clarity.

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?

The description gives no guidance on when to use this tool versus alternatives, no prerequisites, and no exclusions. An agent is left to infer the appropriate context for a search-query length count.

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