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

Adds real behavioral context beyond the annotations: it enumerates the possible per-client outcomes (set up / already set up / can't be automated and why / not installed) and the follow-up step required (restart the app or open a new session). Given destructiveHint=true, it does not say whether existing config entries are merged, overwritten, or backed up — a meaningful omission for a config-mutating tool.

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 the target, and every sentence carries information about scope, targeting, or results. The long inline client catalog duplicates the schema enum (and is inconsistent with it, omitting opencode, goose, hermes, raycast, msty, cherry-studio), which is wasted length.

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?

Output schema exists, so return values needn't be spelled out, yet the description still summarizes result states and next steps. For a destructive config mutation it should also cover merge/overwrite/backup behavior, which is the remaining gap.

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 100%, so both parameters are already documented, including the valid client ids and that `confirm` is ignored. The description only restates 'Optionally pass a single `client` id' and lists a partial subset of clients, adding little beyond the schema baseline.

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 ('Adds Local MCP to the config of the MCP-capable AI apps installed on this Mac') and names the catalog it draws from, so the agent knows exactly what is being modified. It is clearly distinguishable from siblings like list_missing_permissions and lmcp_install_upgrade.

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 concrete usage instructions: omit `client` to configure all installed apps, pass a single id to target one, and 'Pair with list_missing_permissions for fully agent-driven setup.' No explicit exclusions or when-not-to-use guidance, which keeps it below a 5.

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