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

readOnlyHint=true already tells the agent this is a safe read. The description adds the newest-first ordering and the underlying REST path, which is useful context, but says nothing about pagination behavior, rate limits, or result shape beyond what the schema's iterator field already documents.

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?

Two sentences, front-loaded with the core purpose and ordering; the REST path is borderline redundant but compact and aids cross-referencing. 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 read-only list tool with no output schema, the description covers purpose, scope, and ordering, and the schema documents pagination and filters. Missing only an explicit note on the return shape, which is a minor gap.

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 only gestures at status filtering and adds no format, allowed-value, or interaction detail beyond what each parameter description already provides.

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 (list) and resource (delivery attempts) scoped to a single endpoint, plus the ordering (newest first). This distinguishes it from svix_list_attempts_by_message by implication, though it does not name that sibling explicitly.

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?

"Filter by status to find the failures" gives one implied use case, but there is no when-to-use vs alternatives guidance and no mention of when to prefer svix_list_attempts_by_message or other attempt-related tools.

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