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

The description discloses that the query is discarded, implying no side effect for that parameter. However, it does not clarify what happens to the other eight parameters, whether they are also discarded or ignored, nor does it state the return value (e.g., a number). With no annotations provided, the description carries the full burden, which is unmet for a tool with such a broad schema.

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, efficient and front-loaded with the action. It avoids unnecessary detail and is easy to parse. However, the brevity borders on under-specification given the tool's complexity, but for conciseness alone it earns a 4.

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 optional parameters, no output schema, and no annotations, yet the description only addresses a single 'query' parameter. It fails to explain the purpose of the other parameters, how they are used (or ignored), or what the output looks like. This is severely incomplete for an agent to safely invoke the tool correctly.

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 coverage is 100% with each parameter having a description, so the schema already documents the parameters. The description adds no additional meaning beyond what the schema provides—it merely restates that the query is discarded after the length check, which is already in the schema. Baseline 3 is appropriate.

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 action: 'Count characters in a search query' and notes the query is discarded. However, the input schema contains 9 optional parameters, many of which (url, city, feed, host, json, path, zone) are unrelated to a 'search query', so the tool's actual scope is ambiguous. It also does not differentiate from sibling counting tools like uuencode-len or memory-key-count.

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 only mentions counting characters in a search query, with no mention of exclusions, prerequisites, or contexts where another sibling tool would be more appropriate.

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