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

With no annotations, the description carries the behavioral disclosure burden. It adds concrete behavioral details: results are ordered newest first, and the tool is billed per page. It does not mention auth requirements or response shape, but for a read-only listing tool the disclosed details are reasonably complete.

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?

Three short sentences with zero filler. The purpose is front-loaded, followed by billing and the key parameter constraint. Every sentence earns 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 simple listing tool with no output schema and no annotations, the description covers the inputs, the core behavior, ordering, and cost. It is missing only explicit guidance on what response shape to expect, but that is largely inferable from 'users who reposted.'

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%, so the baseline is 3, but the description adds meaningful constraint information beyond the schema: exactly one of url or post_id must be provided. It also ties billing cost to the pages parameter, which helps agents reason about usage cost.

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 users who reposted a Bluesky post.' It also adds ordering ('newest first'), and the term 'reposted' clearly differentiates it from sibling tools like bluesky_post_likes and bluesky_post_comments. This is unambiguous and immediately actionable.

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 gives clear parameter usage guidance ('Provide exactly one of url or post_id') and billing context, but it does not explicitly state when to choose this tool over alternatives. Usage is implied by the tool's name and purpose rather than spelled out.

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