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

Annotations already carry the safety profile (readOnlyHint=true, destructiveHint=false, openWorldHint=false), so the bar is lower. The description adds that stats are 'public' and period-scoped, but says nothing about metric lag or data freshness — which the schema clearly considers a behavioural subtlety worth explaining in both date parameters.

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?

A single sentence with no waste beyond the boilerplate opener 'This tool is used to'. The metrics list is front-loaded and useful, so the sentence earns its place, though trimming the framing would make it tighter still.

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?

With an output schema present, a fully documented four-parameter schema, and annotations covering safety, the description need only establish scope — which it does. The remaining gap is routing advice versus social_account_stats_list, a minor omission for a low-complexity read tool.

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 the baseline is 3 regardless of the description. The phrase 'for the given period' faintly signals the since/until/period trio but adds no syntax, defaults, or metric-lag context beyond what the schema already documents.

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 ('get the public stats of a competitor') and enumerates the metrics returned (followers, views, likes), which lets an agent distinguish it from post-listing siblings. It does not explicitly name its closest sibling, social_account_stats_list, so the competitor-vs-owned-account distinction rests on the parenthetical gloss 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?

Usage is only implied: the tool obviously answers 'stats for a tracked competitor,' but there is no statement of when to prefer it over social_account_stats_list or social_competitor_posts_list, and no prerequisites such as having created the competitor first. The competitor_id parameter description does point at social_competitors_list, which helps indirectly.

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