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

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so the safety profile is covered. The description adds meaningful scope context beyond that: metrics are lifetime, include posts made outside PostQuest, and are bounded by plan history. It does not mention pagination or rate behavior, keeping it just short of a 5.

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 short sentences with the core purpose front-loaded and no redundant filler. It is compact, though the middle 'Limited to the plan history' sentence is slightly terse and could be merged or clarified.

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?

An output schema exists, so return values need not be explained, and the schema richly documents the 7 optional parameters. The description supplies scoping context (lifetime, plan history, external posts), but omits sibling differentiation in a crowded analytics toolset, leaving a minor gap.

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 86%, so the schema already documents sort, limit, range, platform, post_id and social_account_id in detail. The description's only parameter-related content is 'Sortable by metric,' which merely restates what the schema's sort enum provides, so the baseline 3 is appropriate.

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 ('Lists') and resource ('lifetime metrics per published post on connected accounts'), plus a scope note that it includes posts made outside PostQuest. However, it never distinguishes itself from close siblings like get_post_analytics or get_analytics_summary, so an agent cannot tell them apart from the description alone.

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?

No when-to-use or when-not-to-use guidance is given, and the near-identical sibling get_post_analytics is never named as an alternative. The 'Limited to the plan history' clause is a data-scope constraint, not usage routing, so the agent must infer selection from the name alone.

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