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

Adds substantial context beyond the destructiveHint annotation: it is idempotent ('new (or already-existing) recipient'), it mutates existing checks by default via the selection side-effect, and it requires the read/write API key. This explains why destructiveHint=true on a seemingly additive operation. Minor gaps remain (no rate-limit or duplicate-handling detail).

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 but front-loaded: purpose first, then return value, then the important default side-effect, then prerequisites and auth. Every sentence carries distinct, non-redundant information.

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 mutation tool with no output schema, the description covers auth requirements, the selection side-effect, idempotent return behavior, and an external prerequisite. Nothing an agent needs to call it correctly is missing.

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 coverage is 100%, so all four parameters are already documented with types, enums, and defaults. The description reinforces the type list and the selected=false behavior but adds no syntax or format detail beyond what the schema already supplies; baseline 3 is appropriate.

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+resource ('Add an alert recipient') and enumerates the exact accepted recipient kinds (email, sms, webhook, slack_compatible, msteams). An agent can distinguish this from updown_list_recipients without opening either 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?

Provides clear context: the default is to attach the recipient to ALL existing checks, pass selected=false to leave it unattached, and Slack/Telegram/Zapier/Statuspage integrations must be pre-configured in the web UI. It does not explicitly name sibling alternatives (e.g. use list_recipients to view), so it stops short of full when/when-not routing.

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