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

Annotations already declare readOnlyHint and idempotentHint, so the safety profile is covered; the description adds value beyond them by disclosing that the call is free and that authentication depends on a secret issued only at creation time. It does not describe failure modes (e.g. expired secret), which keeps it short of a 5.

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?

A single dense sentence that front-loads the payoff ('Free:') and then lists returned fields, with no filler. The parenthetical field lists are compact and readable, though the long enumeration makes it slightly list-like rather than prose.

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, so enumerating the returned fields (state values, next check, last result contents, webhook counters) is exactly the compensating information an agent needs. The auth requirement is also covered; only error/expiry behavior is left implicit.

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% and both parameters carry descriptions, so the schema already does the work. The sentence 'Needs watch_id and the secret returned when it was created' restates the schema's own wording rather than adding format or sourcing detail beyond it, so the baseline 3 applies.

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?

The description clearly identifies the resource (a watch) and the operation (retrieve its status), and enumerates exactly what is returned: state, interval, expiry, next check, last result and webhook counters. It does not explicitly name a sibling it differs from, but 'watch_status' plus this content is unambiguous against watch_cancel or watch_mcp_server.

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?

The leading 'Free:' signals a cost consideration (no credit charge), which is a genuine usage hint, and the description notes the credentials required to call it. However, it never states when to prefer this over watch_mcp_server or check_mcp_server, nor any when-not condition.

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