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

Goes well beyond the annotations: disclosed version bumping and a full confirmation protocol (status='confirmation_required', action_id, plan_token, then confirm_action). The destructiveHint=true is consistent with a version bump plus confirmation gate. It does not say whether omitted fields are preserved or cleared, which matters for a 7-param partial update.

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?

Front-loaded with the action and field list, then the reach constraint, then the confirmation block. Every sentence adds information; no restating 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?

No output schema exists, and the description supplies the relevant return signal (status plus action_id/plan_token). For a mutation with nested object params, the missing piece is partial-update semantics and whether validation errors are returned before or after confirmation.

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 burden; it names six of the seven properties and their meaning (status enabled/disabled, expose_as_tool, input/output schema). Nested input_schema/output_schema shapes and the maxLength constraints remain undocumented anywhere.

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?

States a specific verb and resource ('Update a sandboxed user function') and scopes it two ways: fields editable (code, description, schemas, status, expose_as_tool) and reach ('in the caller's workspace'). This makes it trivially distinguishable from get_function, create_function and delete_function.

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?

Gives the invocation recipe ('Pass function_id plus the fields to change') and a hard exclusion ('Only the caller's own function is reachable'). It stops short of naming alternatives or when to prefer delete/recreate over update.

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