Get X post metrics

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

With no annotations provided, the description carries the transparency burden. It states 'Read-only,' which is a meaningful behavioral disclosure, and 'lifetime public metrics' clarifies the scope (only public, lifetime data). It also lists the exact metrics returned, adding value beyond the tool name and schema. It does not cover rate limits or error behavior, but for a simple read-only fetch, this is adequate.

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?

The description is a single, well-structured sentence that front-loads the primary action and resource, then lists the specific metrics and constraints. Every word adds value, and there is no redundancy or 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 tool with one parameter, no output schema, and no annotations, the description is sufficiently complete: it specifies the operation, the data returned, the cardinality limit, and the read-only nature. It could add error handling or format details, but the low complexity and clear sibling context make this adequate.

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?

The schema covers 100% of the single parameter with a description ('Post ids to look up (max 100)'). The tool description reiterates 'up to 100 post ids' but adds no additional semantic meaning beyond what the schema already provides. The baseline of 3 applies because the schema does the heavy lifting.

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 description starts with a specific verb 'Fetch' and clearly identifies the resource: 'lifetime public metrics (impressions, likes, reposts, replies, quotes, bookmarks) for up to 100 post ids.' This fully distinguishes the tool from sibling tools, which focus on drafts, accounts, DMs, and retweets, not post metrics.

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 description implies usage by specifying the exact purpose and limits ('up to 100 post ids'), and the 'Read-only' tag indicates it is a safe lookup operation. However, it does not explicitly state when not to use it or mention alternative tools for other metric types, though no obvious alternative exists among siblings.

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