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

readOnlyHint=true already tells the agent this is a safe read, so the description's main added value is the list of returned fields, which is useful given there is no output schema. It does not disclose pagination behavior or result ordering, so it adds only modest context beyond the annotations.

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 short fragments with no filler; the resource statement and returned fields come first. The trailing 'FireText: /keywords.' is minor API trivia rather than agent-facing guidance, but it costs almost nothing.

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 paginated read-only list tool with a fully documented schema and a readOnly annotation, the description supplies the missing piece (what fields come back) and nothing essential is absent. Pagination guidance is already covered by the schema.

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 pp, page and subaccount are fully documented in the schema itself (including the sub-account module caveat). The description adds nothing about parameter semantics, 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 title and description together give a clear verb+resource: list the SMS keywords on the account, and it even enumerates the returned fields (keywordID, number, keyword, reference). It does not explicitly distinguish itself from siblings, but 'keywords' is unique among the report/message/contact tools, so an agent can select it confidently.

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?

There is no when-to-use or when-not-to-use guidance, no mention of prerequisites (e.g. sub-account module), and no alternatives named. The agent must infer that this is simply the keyword-listing operation.

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