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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds genuine value beyond that by stating ordering ('newest first') and enumerating the returned fields (id, title, text, url, published_at in ISO 8601 UTC) plus the site page link — information no annotation supplies, and there is no output schema to carry it. It stops short of mentioning refresh cadence or behavior when no posts exist.

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 sentences, front-loaded with the resource and source, then the return shape. No filler, no restatement of the title, and every clause (source, ordering, fields, page link) carries information an agent would otherwise lack.

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 one-optional-parameter read tool with no output schema, the description is nearly sufficient: it names the source, the ordering, the exact return fields and their timestamp format, and a canonical page URL. Minor gaps remain around empty results and whether repeated calls reflect newly published posts, but nothing critical to correct invocation is missing.

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%: the single 'limit' parameter is fully documented with range (1–25) and default (10) in the schema itself. The description mentions no parameter behavior at all beyond the implicit 'newest first' ordering, so the baseline 3 applies — the schema, not the description, does the explanatory work.

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?

Uses a specific verb ('Lists') plus a precisely scoped resource ('the newest AI Agent News posts shown on austinsdomain.com') and names the underlying source (@Austinsdomain on X). This is unmistakably distinct from the bot/vote/board siblings, so an agent can select it without opening any other 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?

Usage is only implied: reading recent news posts. There is no explicit statement of when to prefer this tool over siblings, nor any 'do not use for X' exclusion or prerequisite (e.g., whether it needs auth or is safe to poll).

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