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 says 'Query discarded' but doesn't clarify that the other 8 parameters are ignored or what happens with them. It doesn't mention side effects, storage, or the fact that it's a pure length computation. The presence of many unrelated parameters without explanation is a transparency gap.

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 with no fluff. It front-loads the core purpose and includes the key side effect (query discarded). This is appropriately concise for a simple 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?

The tool has 9 parameters, none required, and no output schema or annotations. The description only explains the query parameter's purpose, leaving the other 8 parameters unexplained. The tool appears to be part of a family of shape/validation tools, but its name and description don't clarify why it accepts url, city, etc. This makes the definition incomplete for an agent trying to use it 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 description coverage is 100%, so each parameter has a description in the schema. The description itself adds minimal value beyond stating 'query' is the focus. It doesn't explain why url, city, feed, etc. are included or how they relate to the tool's purpose. Since the schema already documents each parameter, the baseline is 3, but the description fails to clarify the interplay between parameters.

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 'Count characters in a search query' which is a specific verb and resource, and the name 'search-query-len' reinforces this. It doesn't explicitly differentiate from other count tools like memory-key-count or hn-front-count, but the resource is distinct enough. The primary purpose is clear, though it doesn't mention the other parameters.

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 description provides no guidance on when to use this tool versus alternatives. It doesn't state any conditions, exclusions, or context for calling it. The schema has 9 optional parameters, but there's no instruction on which ones are relevant or how to choose this tool over sibling tools like domain-shape or calc-eval.

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