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

Annotations only declare the safety envelope (not read-only, open-world, not idempotent). The description adds genuinely non-obvious behavior: that the account password is refused, that anything other than the xxxx-xxxx-xxxx-xxxx format is refused, and the exact error code (bluesky_app_password_required) returned on failure. That is real additional transparency.

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?

Front-loads the core action and the credential restriction, then supplies format and a creation link. Efficient, though the password format is repeated from the schema, which is minor redundancy.

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 connect tool with no output schema, the description covers everything an agent needs: required credential type, format, how to create it, and the failure mode. Nothing material is missing.

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 both parameters are already documented in the input schema, including the app-password format and the identifier flexibility. The description's restatement of the format is largely redundant; baseline 3 applies.

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 verb and resource ('Connect a Bluesky account') and distinguishes itself from the sibling connect_* family (facebook, instagram, x, etc.) by naming the platform in the tool name and title. An agent can route to it without opening a schema.

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?

Gives clear context for how to obtain the required credential (app password created under Settings > Privacy and Security) and the exact URL, which is strong practical guidance. It does not explicitly name sibling alternatives or state when not to use this tool, so it stops short of a 5.

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