search_by_extension

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

No annotations are provided, so the description carries the full burden. It only mentions the search capability without disclosing whether searches are recursive, how results are ordered, any default limits beyond the schema's maxResults, or that it is a read-only operation.

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 sentences and front-loaded with the core functionality. The second sentence, 'Fast way to find all files of a certain type,' is slightly redundant but does not significantly waste space.

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 no annotations and no output schema, the description should clarify the return format (e.g., file paths), recursion behavior, and the relationship between type='custom' and customExtensions. These practical details are absent, leaving the agent to infer critical execution context.

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 descriptions cover 100% of the 5 parameters, so the baseline is 3. The description adds context by enumerating type categories and mentioning custom extensions, but it doesn't add meaning for path, pattern, or maxResults beyond what the schema already provides.

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 it searches for files by type category or custom extensions, distinguishing it from sibling tools that filter by recency, size, or path. The verb 'search' and resource 'files' are specific, making the purpose unambiguous.

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 phrase 'Fast way to find all files of a certain type' implies usage for finding files by type, but it does not explicitly state when to prefer this tool over sibling tools like search_files or search_in_path, nor does it mention any exclusions or alternatives.

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