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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so safety is covered by structured data. The description earns credit for disclosing the payload contents (per-destination id, paused state, plan limit and used count) in the absence of an output schema, plus the constraint that this is read-only w.r.t. destination creation. It stops short of stating ordering, pagination, or behavior when the plan limit is reached.

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?

Four short sentences, front-loaded with what the tool returns, then the reason to call it, then the sibling contrast, then the out-of-band creation note. Nothing repeats the title or the annotations, and every sentence carries distinct routing or payload 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 zero-parameter read tool with no output schema, the description compensates by describing the return shape and the downstream use of the returned ids. Combined with the plan limit/used count disclosure, an agent has everything needed to call it and interpret the result.

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?

The tool takes zero parameters, so the baseline of 4 applies; there is nothing for the description to disambiguate. The description correctly signals that the tool operates on the whole account scope rather than a filterable subset.

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 ('Lists the account's alert destinations') and immediately bounds the scope (Slack, Discord and other channels besides email). It also enumerates the returned fields (id, paused, plan limit, used count), so an agent can distinguish it from list_views and list_watchlist without opening a 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 an explicit positive trigger ('Use it to find a destination id for create_view or update_view') and names the sibling that answers the complementary question ('list_views shows which Views deliver to each'). It even closes the loop on the out-of-scope action: new destinations are added in the web app under Settings, so the agent knows not to look for a create tool.

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