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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered. The description adds genuinely useful behavior: failed fetches are retained with their error and ranked last, and each row mirrors get_post_stats' shape, which is exactly the kind of degraded-result handling an agent needs and annotations cannot express.

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 sentences, zero filler; the count/platform constraint leads and the output and error behavior follow. Every clause carries distinct information.

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 fields needn't be enumerated, and the description still covers input scope, ranking, derived metric and error retention. Nothing an agent needs to invoke and interpret this 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?

With a single parameter and 100% schema description coverage, the schema already documents the meaningful constraints (2-10 items, platform mixing, full addresses). The description restates the same 2-10 and mixed-platform facts, adding no syntax or format detail beyond the schema, 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 (read/rank) and resource (2-10 public posts) plus the ranking key (views) and the derived metric (likes per 1,000 views). It also distinguishes itself from the sibling get_post_stats by saying rows share its fields, so an agent can tell the two apart without opening a schema.

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 clear usage bounds — 2 to 10 posts, platforms may be mixed, public posts only — which tells the agent when this tool applies versus a single-post lookup. It never explicitly says when not to use it or names get_post_stats as the single-post alternative, so it stops short of full routing guidance.

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