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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint, so safety is covered. The description adds one genuine behavioral caveat — 'as far as the platform shows them' signals results may be truncated by platform visibility rules — but leaves 'counts as browsing' unexplained and says nothing about pagination, ordering, or privacy of the results.

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 short sentences with the resource stated first and no padding. However, the second sentence is an unexplained fragment whose meaning an agent has to guess, so it is not fully earning its place.

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 read-only, cursor-paginated list tool with no output schema, the description covers what is returned but not how to page through it, what ordering 'recent' implies, or what an empty result means. Adequate to invoke, thin for using the results reliably.

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 75%, and the description adds no meaning beyond the schema: it never mentions user_id (username vs id), account_id, limit or cursor. The schema carries most of the weight, with the interesting detail about Instagram follower pages page sizes living there rather than here.

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 resource and direction: 'Recent likes and reactions by a person' makes clear it retrieves reactions the given user authored, not reactions on a user's content. It does not name or distinguish itself from near-neighbours like list_post_reactions or list_comment_reactions, so an agent must still infer the distinction from the resource wording 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?

'Counts as browsing' gestures at the read-only nature of the call but gives no when-to-use condition, no exclusions, and no pointer to alternative tools for post-, comment- or message-level reactions. The agent gets no help deciding between this and the many other reaction-listing siblings.

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