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

Annotations only cover safety hints (readOnly=false, idempotent=false, destructive=false); the description adds substantial behavioral context beyond them: webhook secret is shown once and must be stored, webhook signing via Standard Webhooks headers, email instant-vs-daily semantics, and plan quotas (Free 5 / Builder 50 / Pro 500) with the note that alert calls don't consume the monthly allowance.

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?

Purpose is front-loaded and the Target/Channels/Examples/Returns structure is easy to scan. It is dense and runs long for a tool description, but each block (targeting modes, channel options, example payloads, quota limits) carries information an agent needs, so little is wasted.

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?

There is no output schema, and the description compensates by describing the return shape ({alert: {...}, created, secret?, warnings?}) including the one-time secret. Combined with quota limits, channel behavior, and prerequisites (workspace_list for item ids), it is complete for a 9-parameter creation tool.

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 already 100%, so the baseline is 3, but the description adds real meaning beyond the schema: the mutual exclusivity of indicator/place versus workspace_item, and the conditional applicability of channel-specific params (email_mode only for email, webhook_url only for webhook). It stops short of fully documenting every field, but the added semantics are meaningful.

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?

Starts with a specific verb+resource ('Create an alert') and immediately defines the trigger condition (new period published or a value revised). It distinguishes itself from sibling alert tools (list_alerts, update_alert, delete_alert) and from get_value/search_indicators by naming them as dependencies rather than alternatives.

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 use-case phrasings ('notify me when Spain's CPI is out'), states the two mutually exclusive targeting modes (indicator+place vs workspace_item) with plan gating, and routes agents that want polling to the 'feed' channel + list_changes instead. Alternatives and exclusions are explicit.

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