Rename a mod file

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

Annotations already declare readOnlyHint=false and idempotentHint=true, so the write/repeat-safety profile is partly covered. The description adds real context beyond them: the rename applies to the entire update chain, and it requires the NEXUS_ALLOW_WRITES environment flag to be enabled.

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 short sentences with zero filler; scope, prerequisite source, and write gate are front-loaded in that order.

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 a two-parameter mutation with full schema coverage and no output schema, the definition covers scope, ID provenance, and the write prerequisite. It could note behavior on invalid names or partial failure, but nothing essential is missing.

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%, documenting both mod_file_id and the new-name character constraints. The description reinforces the provenance of mod_file_id but adds no syntax or format detail beyond the schema, so 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 (rename) plus resource (mod file) with a clarifying scope note that it affects the whole update chain rather than a single version. This distinguishes it from version-level operations in the sibling set.

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?

Tells the agent where to obtain mod_file_id (nexus_mod_file_targets) and states the write-operation prerequisite (NEXUS_ALLOW_WRITES=true). No explicit when-not-to-use guidance, but the routing context is clear.

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