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

With no annotations, the description carries the behavioral burden. It transparently states the core behavior (character counting) and non-retention of the query, which is useful for privacy. However, it does not disclose what happens if other schema properties are supplied, the return format, or how characters are counted.

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?

Two short sentences, with the core action front-loaded and no filler. Every word contributes to the meaning.

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?

Despite the simple intent, the tool exposes a confusing 9-field optional schema with no output schema and no annotations. The description does not explain which field to populate, whether other fields are ignored, or what an empty call returns, so an agent cannot confidently construct a correct invocation.

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 even though the description adds no parameter-level detail. The description's 'search query' maps naturally to the `query` property, but the presence of eight other optional parameters is never reconciled, leaving ambiguity about whether only `query` should be sent.

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 operation — count characters in a search query — and adds a privacy-relevant detail that the query is discarded. It is not a tautology and differentiates this length-counting tool from shape-checking siblings, but it does not tie the described 'search query' to the `query` parameter among eight unrelated optional fields.

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, when to avoid it, or which sibling to prefer. The description provides no context such as 'use when you need the length of a search string before calling a search API' and no exclusions.

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