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

Annotations already establish readOnlyHint=true, destructiveHint=false and openWorldHint=true, so safety is covered. The description adds genuinely useful behavior: one credit per successful request including empty results, repeated requests may re-purchase data, and a terminal-page path that costs nothing. However, the cost statements are internally muddled ('one credit per request' vs. 'at least 10 Nexscope credits'), which leaves the agent uncertain about actual billing.

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?

The same content is repeated roughly three times, including a duplicated paragraph and appended 'View Pricing' navigation text. The useful pagination rule is front-loaded, but the bulk of the text is redundant and the conflicting credit figures add noise rather than clarity.

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 paginated list with no output schema, the description does mention the relevant response fields (has_more, end_of_pagination) and the cost model, which is enough to page through results. But the contradictory credit costs and absence of output-shape detail beyond pagination flags leave it only adequate.

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 coverage is 100%, and the schema already explains passing the previous cursor unchanged, stopping at null, and the literal string "null" returning an empty terminal page without charging. The description restates these cursor semantics rather than extending them, so it adds little beyond the schema. 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?

The description states a specific verb and resource: 'Get the public posts saved to a Cosmos user profile,' with the scope qualifier 'Public data only.' An agent can tell this returns a user's saved posts rather than a single post or cluster feed. It does not, however, name or distinguish itself from siblings like social_cosmos_profile, social_cosmos_cluster_posts, or social_cosmos_user_clusters.

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 gives operational guidance for pagination: keep the cursor unchanged and stop when has_more is false. But it never says when to choose this tool over the sibling cluster-posts or profile tools, so selection guidance is only implied by the tool name and first sentence.

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