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

No annotations are provided, so the description must carry the full burden of behavioral disclosure. It mentions 'Query discarded,' which hints at non-persistence, but does not state whether the tool is read-only, whether it has side effects, what it returns, or how it treats the other parameters. The behavioral profile is largely undocumented.

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 short, but this is under-specification rather than conciseness. It lacks necessary context about the tool's full scope. There is no front-loading of critical information because the entire description is just one vague sentence.

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?

With 9 parameters and no output schema, the description is severely incomplete. It does not explain what the tool returns, how it handles multiple inputs, or why such a diverse set of fields exists. An agent cannot reliably invoke this tool without additional inference.

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 input schema descriptions are thorough, covering all 9 parameters with details like 'discarded after the shape check' and 'no disk access.' Since schema coverage is 100%, the baseline is 3. The description adds no additional meaning beyond the schema, so it does not improve parameter understanding.

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 says 'Count characters in a search query,' which names a verb and a resource, but the schema exposes 9 unrelated parameters (ref, url, city, feed, host, json, path, zone) with no explanation of their role. This makes the purpose ambiguous and likely misleading – it does not clarify whether the tool processes only 'query' or all fields. It also fails to differentiate from sibling counting tools like memory-key-count or hn-front-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?

There is no guidance on when to use this tool versus alternatives. No mention of typical use cases, prerequisites, or exclusions. The description is a single sentence with zero context about selection criteria.

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