List Transactional SMS

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

Annotations already declare readOnlyHint=true, destructiveHint=false and idempotentHint=true, so safety is covered. The description adds a useful presentation constraint ('don't read ids or timestamps back unless asked'), which is real behavioral guidance beyond the structured fields, though it says nothing about pagination or result size.

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 sentences, front-loaded with the core purpose followed by the disambiguating definition. All sentences carry information, though the closing id/timestamp instruction is presentation guidance rather than invocation-critical content.

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?

A simple read-only list tool with no output schema and fully documented parameters; the description adequately scopes the resource and gives output-presentation guidance. It is complete enough for correct invocation, missing only optional pagination commentary that the schema already covers.

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 all three cursor/limit parameters are fully described in the schema, so the baseline of 3 applies. The description adds no pagination syntax or format detail beyond what the schema 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 and resource ('List transactional sms') plus the returned content ('delivery status'), and explicitly carves out what transactional means versus campaigns, which cleanly distinguishes it from the sibling list-sms-campaigns. An agent can differentiate this from the other list-* tools 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?

The definition of 'transactional' (one-off sends like receipts and OTPs, not campaigns) gives clear context for when this list is the right one. It stops short of routing the agent to a concrete alternative such as get-sms-message for a single message, so it lacks explicit exclusions.

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