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

Goes well beyond the annotations: exact return payload ({"status": "DELETED", ...}), the side effect that open streams receive a `closed` frame within one read cycle (<= 8 s), the 404 unknown subscription_id behavior (including another user's id), rate limits, and the OAuth requirement. The idempotent/destructive hints are confirmed rather than repeated.

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?

Front-loads the operation and endpoint, then layers return shape, streaming side effect, error case, rate-limit rationale, and auth in compact sentences. Slightly dense with parentheticals, but every sentence carries decision-relevant 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?

Covers the full call surface: auth requirement, error semantics, post-delete streaming consequence, and the rate-limit context that motivates using this tool at all. With an output schema present it need not describe returns further, yet its extra detail is accurate and helpful rather than redundant.

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%, and the schema already ties subscription_id back to register_event_subscription's return value. The description restates the identifier but adds no format, syntax, or lookup detail beyond the schema, so the baseline of 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?

States a specific verb and resource ('Remove a saved event subscription') and even names the HTTP route, so there is no ambiguity about the operation. It does not explicitly name or contrast itself with siblings like register_event_subscription or stream_event_subscription, so it falls short of the top tier that requires sibling differentiation.

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 genuine operating guidance: because registrations are rate-limited (30/hour), the agent should delete subscriptions the user is done with rather than re-registering each session. This implies the when-to-use context clearly, though it does not name an alternative tool explicitly or state hard exclusions.

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