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

No annotations are provided, so the description carries the full burden. It usefully discloses billing ($0.003 per page) and ordering (newest first), but does not mention rate limits, error behavior, or explicitly confirm it is read-only. These disclosures add meaningful context beyond the raw schema, but gaps remain.

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 with no wasted words. The first sentence states action, resource, and ordering; the second covers billing and the parameter rule. Everything earns its place and is front-loaded.

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 simple read-only list tool with no output schemaaca, the description captures purpose, ordering, cost, and the parameter exclusivity rule. The schema handles details like page size and defaults. The only minor omissions are rate-limit or auth notes, which are uncommon in this context.

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?

The schema already documents all three parameters with 100% coverage, establishing a baseline of 3. The description adds the crucial exclusive-or constraint ('exactly one of username or url'), which is not present in the schema, and clarifies the output ordering. This extra meaning raises the score above baseline.

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 ('Get') and resource ('followers of a Bluesky user') with ordering ('newest first'). This clearly distinguishes it from the sibling tool bluesky_user_following, which retrieves the opposite relationship.

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?

The description provides no guidance on when to use this tool versus alternatives such as bluesky_user_following or search_bluesky_users. The only directive, 'Provide exactly one of username or url', is a parameter constraint, not a tool-selection guideline.

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