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

With no annotations, the description carries the full burden. It usefully discloses scope semantics ('every report you own, were invited to, or share with your team (public link access doesn't count)') and defaults, but says nothing about authentication needs, whether deliveries are verified, rate limits, or failure behavior.

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?

Three tight sentences with the core purpose front-loaded, followed by scoping and defaults. The defaults sentence partially duplicates schema fields but still reads efficiently with no filler.

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 6-parameter create tool with no annotations and no output schema, the description covers purpose, scoping, and defaults adequately but omits prerequisites, whether a notification identifier is returned for later use, and any note on delivery/verification behavior.

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 the baseline is 3. The description repeats the events and format defaults already documented in the schema and adds only the 'public link access doesn't count' nuance for report_id, while saying nothing about name or signing_secret (both already covered by the schema).

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 opening sentence states a specific verb and resource ('Subscribe a webhook to report events'), which clearly separates it from list_notifications and delete_notification. It does not, however, differentiate from the potentially similar create_connector sibling, so it falls short of a 5.

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 report_id omission rule and the events/format defaults give clear operational context, but this is parameter-usage guidance rather than tool-selection guidance. There is no statement of when to use this instead of connect_integration or create_connector, nor any exclusions.

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