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

Annotations already cover the safety profile (readOnlyHint=true, destructiveHint=false, openWorldHint=true), so the bar is lower. The description adds real context beyond that: it covers posts not created through Breakreach, enumerates the metric families the platform exposes, and discloses that a benchmark comparison against the account average is included. No pagination, rate-limit, or error behavior is mentioned.

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?

Front-loaded with the payload summary in the first clause, followed by the required-parameter sourcing note. The parenthetical metric enumeration is long but earns its place given there is no output schema to describe return values. Slightly list-heavy but no filler sentences.

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 no output schema, the description correctly takes on the return-value burden by enumerating metrics, comments, and the average comparison. It also names the id source, so an agent can chain the call. Minor gap: nothing about behavior for invalid postIds or what a missing-benchmark case returns.

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 schema already documents all three parameters, including that postId is 'the platform post id' and accountId comes from list_accounts/get_content_performance. The description restates the same sourcing guidance without adding format, validation, or edge-case detail. Baseline 3 applies when the schema carries the weight.

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 and resource ('everything about one post on a connected account') and enumerates the scope: caption, media, lifetime metrics, comments, and an average-post comparison. This distinguishes it from the overlapping siblings get_post_metrics and get_post_comments by framing itself as the comprehensive superset, and it notes the unusual inclusion of posts not published with Breakreach.

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?

It does give the prerequisite for the ids ('Take accountId and postId ... from get_content_performance'), which is useful routing. However it never states when to prefer this tool over the directly overlapping get_post_metrics or get_post_comments, nor any exclusion. Usage is implied by 'everything about' rather than declared.

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