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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds useful context by specifying the data surfaced (profile details plus follower/following/post counts), though it says nothing about auth requirements or rate limits. Solid but not exhaustive beyond the annotations.

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 zero filler, and the core purpose is front-loaded before the sibling routing. Every clause 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 single-parameter read tool with an output schema and annotations covering safety and scope, the description supplies everything needed to select and call it correctly. Return values are handled by the output schema, so nothing 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 the schema already documents that actor takes a handle or DID. The description restates this ('by handle or DID actor') but adds no format or syntax detail beyond what the schema and its example provide. Baseline 3 is appropriate when the schema does the heavy lifting.

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 (Fetch) and resource (Bluesky account's public profile details plus follower/following/post counts), and explicitly names the sibling tools that handle adjacent data. An agent can distinguish it from bluesky_followers or bluesky_author_feed without opening any 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?

Names each alternative and the condition that selects it: bluesky_author_feed for posts, bluesky_followers/bluesky_follows for relationships, bluesky_search_actors to find accounts. This is explicit routing guidance with no inference required.

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