tc_allow_write

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

Adds substantial context beyond the annotations: the change is session-scoped and lost at next server start, it is audited, the deny list still wins, and it requires confirmation via prompt or confirm_token from tc_request_confirmation. These are exactly the behavioral traits annotations don't cover.

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?

Dense and front-loaded, with the scope and purpose stated first and the operational caveats following. Every sentence carries information, though the parenthetical confirmation sentence is somewhat packed.

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 session-scoped config-mutating tool, it covers scope, persistence, audit, safety interaction (deny list), and the confirmation requirement; an output schema exists so return values need no explanation.

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?

With 0% schema coverage the description carries the full burden and largely does: it explains the pattern syntax (fnmatch, case-insensitive) with concrete examples and identifies the confirm_token source. The only soft spot is the 'target=...<pattern>' removal phrasing, which is slightly conflated with the separate 'remove' boolean.

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 (add/remove a write allow-list pattern) plus an explicit scope ('THIS session only') and frames it against the config-editing alternative. An agent can distinguish it from the many ads_write/xae_* siblings without opening the 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?

Gives clear when-to-use context (in-session alternative to editing twincat_mcp.toml and reconnecting) and the precondition (control-class, needs confirmation). It does not name an explicit when-not-to-use or a sibling tool, so it falls just short of a 5.

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