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

Annotations already declare destructive=true, readOnly=false, and openWorld=false. The description adds valuable CAS/fail-on-absent-or-ambiguous-match semantics beyond the annotations, though it omits atomicity, permissions, and edit-limit behavior.

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?

It is a single front-loaded semicolon clause with no filler. It is concise but arguably undersized for a five-parameter nested mutation tool; however, no sentence is wasted.

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 destructive, five-required-parameter edit tool with no property descriptions and no output schema, one cryptic clause is not enough to guide correct invocation. It communicates failure semantics but leaves workspace, build_id, path, and edits usage unexplained.

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 0% and none of the five required parameters are named or explained. 'CAS' and 'exact replacements' only loosely hint at expected_sha256 and edits, while replace_all and the 20-edit limit are left entirely to the schema.

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 names a mechanism ('CAS exact replacements') and a failure mode, but never plainly states the resource or action: it does not say 'edit a file' or distinguish it from files_write/files_diff. The annotation title helps, but the description alone is cryptic.

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?

It gives no guidance on when to choose files_edit over files_write, files_diff, or files_read, and no prerequisites such as obtaining expected_sha256 first. The failure condition is a behavior, not a usage rule.

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