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

There are no annotations, so the description must carry the transparency burden. It does disclose one behavioral trait beyond the schema—'Query discarded' indicates the input is not retained. However, it does not mention return behavior, side effects, or how multiple provided parameters are treated.

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 no filler; the main purpose is front-loaded and the data-handling note ('Query discarded') earns its place. This is appropriately concise for a simple length-counting tool.

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 9-parameter tool with no annotations and no output schema, the description is too sparse: it does not state what the tool returns, how character counting is defined, or whether only the query parameter is used. The discarded note helps but leaves important invocation and output behavior unclear.

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 tool description adds little parameter detail. The phrase 'search query' maps naturally to the query parameter, but the description does not clarify that the other 8 optional parameters are irrelevant to this tool.

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 names a clear verb ('Count') and a resource ('characters in a search query'), so an agent can understand the core operation immediately. It does not explicitly distinguish itself from sibling count/shape tools, but the search-query object is specific enough to avoid serious ambiguity.

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 directive 'Count characters in a search query' implies when the tool should be used, but there is no explicit when-to-use/when-not-to-use guidance or mention of alternatives. With 9 optional parameters and many sibling tools, an agent gets only an implicit usage cue.

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