split_file_by_declarations

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

Annotations already declare destructiveHint=true and idempotentHint=false, so the safety profile is covered; the description adds real value beyond that by disclosing that dryRun defaults to true (preview-before-write) and that a combining file is optionally generated. It still omits explicit overwrite/destruction semantics, but the default-safe behavior is a meaningful addition.

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?

Three tight sentences: purpose first, then the auxiliary output, then the safety-relevant default. No filler, and the most important information is front-loaded.

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 an 8-parameter mutating tool with no output schema, the description plus fully-covered schema and destructiveness annotations give the agent enough to call it correctly. Minor gaps remain around failure/return behavior, but the schema and annotations carry the rest.

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 the schema already documents all 8 parameters (cwd, file, dryRun, grouping, language, overwrite, targetDir, generateIndex). The description only reinforces dryRun and the combining-file/index concept, adding nothing the schema doesn't already convey. Baseline 3 applies.

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?

Specific verb (Split) + resource (a large file) + mechanism (based on top-level declarations), with the auxiliary combining-file behavior named. It does not explicitly differentiate from potentially adjacent siblings such as generate_module_skeleton or batch_apply_edits, so it stops short of a 5.

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 implies the use case (splitting large files) and gives safety-oriented guidance for the dryRun flag, but never states when to prefer this over alternatives like generate_module_skeleton. Usage is only implied, not routed.

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