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

The description carries the full burden because no annotations are present. It transparently discloses billing per page, newest-first ordering, and the need to provide exactly one identifier, which goes beyond the schema. It does not mention error behavior or response shape, but for a straightforward read operation this is 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?

The description is exceptionally concise: two short sentences pack purpose, ordering, cost, and the critical input constraint with no filler. Each sentence contributes 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?

All three parameters are fully described in the schema, and the description covers purpose, ordering, cost, and input constraints. It lacks explicit error behavior and output shape, but given the simplicity of the tool and the absence of an output schema, the definition provides enough context for an agent to invoke it correctly.

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. The description adds valuable semantics by stating the mutual-exclusivity rule for username and url, which the schema alone does not enforce or explain, and it reinforces the billing implication of the pages parameter.

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 action ('Get the accounts ... follows') on a well-defined Bluesky resource, and clarifies the result ordering ('newest first'). This clearly distinguishes it from the sibling bluesky_user_followers by indicating the direction of the 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?

No guidance is given on when to use this tool versus alternatives such as bluesky_user_followers or other user-related Bluesky endpoints. The only usage rule, 'Provide exactly one of username or url,' concerns parameter selection rather than tool selection.

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