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

With no annotations, the description carries the full burden of behavioral disclosure. It only mentions that the query is discarded, which is a privacy-related detail, but does not state what the tool returns (e.g., an integer count), whether it has side effects, or any error conditions. The behavior is minimally described, leaving significant gaps for an agent that needs to interpret the result.

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 a single, front-loaded sentence with zero fluff. It states the action and a key behavioral fact (discard) efficiently. Every word earns its place, making it very concise.

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 parameters, many of which appear irrelevant (ref, url, city, feed, etc.) and are clearly intended for other tools in a shared schema. The description does not clarify that only the 'query' parameter is used, which could lead an agent to pass unnecessary arguments. Additionally, there is no mention of the output format (e.g., a number) since there is no output schema. Given the complexity of the schema, the description is incomplete.

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%, so all 9 parameters are documented in the schema, including 'query' which is described as 'Search text; discarded after the length check'. The description adds no extra meaning beyond the schema; it just references the search query without explicitly mapping to the 'query' parameter. Since coverage is high, the baseline of 3 is appropriate, though the description does not help disambiguate which of the many parameters are actually relevant 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 clearly states the action (count characters) and the resource (search query), making the tool's core purpose evident. However, it does not differentiate from sibling tools like domain-shape or jira-key-shape, all of which appear to be shape-check/validation tools with similar one-line descriptions. The name itself hints at the specific use, but the description doesn't name any alternatives.

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 the many siblings, nor any mention of exclusions or prerequisites. The description is a single sentence with no context about scenarios where this tool is appropriate. An agent would have to infer usage from the name alone.

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