Per-post metrics

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

Annotations already declare readOnlyHint, idempotentHint, and openWorldHint, so safety is covered. The description adds real behavioral context beyond them: metrics are per-post and may include a time series 'where snapshots exist', disclosing that trends are conditional and not always available.

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 tight sentences with no padding: the first defines the output, the second defines the trigger. The routing condition is placed after the purpose, keeping the key subject front-loaded.

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 two-parameter read tool with no output schema, the description covers what the metrics are, that trend data is snapshot-dependent, and when to reach for it. It could say more about what a snapshot gap means for the response, but nothing essential to invoking the tool correctly 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%, so both parameters are already documented, including that postIds come from list_posts and workspaceId defaults to the active workspace. The description's 'by id' phrasing adds nothing the schema doesn't already say, 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?

States a specific verb+resource ('Metrics for specific posts by id') and immediately scopes it to per-post rather than workspace-wide, which is exactly the distinction the agent needs against get_analytics. The added note about movement over time further sharpens what kind of metrics are returned.

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?

Gives an explicit trigger ('Use after list_posts when the question is about particular posts rather than the workspace as a whole'), which effectively routes the agent away from the workspace-level analytics tool. It stops short of naming that sibling tool outright, but the condition that selects this tool is unambiguous.

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