st.source.write

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

With no annotations, the description carries a heavier burden. It does disclose a key behavioral requirement: confirm must be true and snapshots must be taken first. However, it omits other behavioral traits like overwriting behavior, path validation, rollback implications, or return value. It is helpful but incomplete.

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 a single sentence with no wasted words. It front-loads the core purpose and then adds the most important prerequisite, making it compact and readable.

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 tool with no annotations, no output schema, and five parameters, this description is too thin. It does not explain how to take a snapshot, whether the operation overwrites, what path format is expected, or what happens when confirm is false. An agent would need more details to invoke it confidently.

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%, so the description must compensate. It adds meaning to 'confirm' by requiring it to be true, and hints at 'snapshotLabel' via 'snapshots first', but it says nothing about 'path' or 'content' beyond their names. The description only partially covers the parameter semantics needed.

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 a specific verb ('Write'), a resource ('source file'), and the allowed scopes ('project-root, st-root, or st-mcp'). This distinguishes it from siblings like st.source.read and st.resource.patch, so an agent can tell what the tool does at a glance.

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 gives important procedural context by stating that confirm: true and snapshots are required before writing, but it does not explicitly say when to prefer this tool over alternatives or when not to use it. Usage is implied rather than fully spelled out.

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