Update snippet

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

Annotations already flag destructiveHint=true and idempotentHint=false, and the description adds real context on top: write scope required, the full file list is overwritten rather than merged, omitted fields are preserved, explicit null clears collection/source, and an edit is recorded in history. The history note also explains why the call is non-idempotent despite replace semantics.

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?

Four short sentences, front-loaded with the destructive replace action, then the mitigation (read first), then the field-by-field preservation rules. No filler and no repetition of the title.

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 8-parameter mutation with no output schema, this covers the important ground: permissions, overwrite breadth, preservation, null semantics, and history. It does not say what a successful response contains or whether files[].lines can be used for partial-file updates, a minor gap given the destructive hint.

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 carries the full burden and largely delivers: it names every optional field (description, visibility, collection, tags, source), states the preserve-by-default rule, and defines explicit-null clearing for collection and source. Only the nested shapes (files[].lines, source.commit/dirty) are left 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?

"Replace the title and entire file list of your live snippet" gives a specific verb (replace) plus the exact resource and scope, and the closing sentence about link/expiry/password/burn settings makes clear this is not the settings-update sibling. An agent can distinguish update_snippet from update_snippet_settings and create_snippet without opening a schema.

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?

"Read it first to keep files you still need" is an explicit prerequisite directing the agent to read_snippet before calling, which is exactly the right routing for a replace-semantics tool. It stops short of naming update_snippet_settings as the alternative for the fields this tool leaves untouched, so the exclusion is implied rather than stated.

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